Eddie’s Office 2013 Theme Mod



Ok guys, I’ve been having my eyeballs burned long enough, and so a couple of days ago I figured I’d give it a go, trying to find a way so sort this out. Shortly after starting out, I found this site which provided some good ideas. I was just about to give up, when I did a final attempt, and it seems to have paid off.

It’s early times, but I’ve managed to replace some colours. I’d figured I’d share what I’ve found so that others can help figure out the rest.

Here is a screenshot of what I’ve managed to achieve: https://dl.dropboxusercontent.com/u/8452679/images/OutlookModifiedColours.png

Step-by-step how I got there:
1. First I switched between different themes to find out which colours changed and then I picked one that stood out. The one I chose was the bottom status bar which is grey in the “Dark Grey” theme, but is light-blue in the “Light Grey” theme. I grabbed a screenshot of the light-blue colour, and grabbed the hex colour code in Photoshop (0067b0)

2. I searched for all the .dll file in the below locations (incl. subdirs) and copied them to a couple of temp folders (Test & Test2).
C:\Program Files\Microsoft Office\Office15
C:\Program Files\Common Files\Microsoft Shared\OFFICE15

3. I opened up a .dll file in HxD (mh-nexus.de/hxd/) and replaced three bytes of HEX with ones from the light-blue colour (replaced “00 00 00″ with “00 67 b0″). This gave me the light-blue equivalent string “.g°”

I used grep to search all the .dll files for this string using the below commands which gave me a list of .dll files.
grep .g° “C:\Test\*.dll”
grep .g° “C:\Test2\*.dll”

4. I opened the files one by one using HxD and then searching for the string. Most of the files didn’t seem to contain colour codes (the strings found were in random places), but in the file MSO.DLL the strings were all lined up with what seemed to be other color code strings.

5. I replaced all the HEX bytes (00 67 B0) found with a pink color (FF 00 FF) and then saved as a new file (MSO.DLL.modified).

6. When I tried to rename the original MSO.DLL file (to MSO.DLL.original), it complained about being in use, so restarted and then it worked. I renamed my modified file to MSO.DLL and then copied this to the original file’s location (C:\Program Files\Common Files\Microsoft Shared\OFFICE15)

7. After starting Outlook, I switched theme from Dark Grey to Light Gray and voila, some colours had changed! Note that the colour of the status bar that I tried chaning didn’t change, so this is most likely defined in another .dll file.

Using the above method, one should be able to change one colour after another to figure out which colours do what and then create a map of all colours that can be changed.



Great job Eddie. I followed your lead with a few teaks and was able to customize the color for the “unread emails” to FF 00 FF. Note to others I did have to force several processes to close that were using the MSO.dll file before I was able to copy my edited version back into the original location.
See Here: https://www.dropbox.com/s/6v3sd0wq0liuk5j/Screen%20Shot%20Custom.jpg?dl=0

– ushadow91

Cheers guys,

Just to let you understand why it’s taking so long. For the dark theme only, there are 2568 colours you can change and a total of 900 unique colours. Not sure what the guys were thinking when designing the themes.

Anyways, I’m mapping whatever I can find visually after changing to random colours. I’m almost done with Outlook, and I’ve mapped about 60 items (backgrounds, text, borders etc.) so far.

Once done I will create a dark theme with maybe 20 colours in total which should help in designing themes going forward. It’s a big job and sometimes I feel like giving up, but it only needs to done once properly for everyone to benefit.

– Eddie

“… I still would like to change the colors to something other than the dark one. Maybe you can give us another update on the location of all the files/reg that need to be mapped. I can maybe help out! I really want this too!


– Jason


Hi Jason,
Sorry I haven’t had a chance to get back into this due to being busy with life 🙂
However I’m still dedicated to finish this off. I do appreciate the offer to help. Let me explain where I’m at and you can decide if you would like to help.
I’ve created two new versions of MSO.dll where I’ve replaced all colours (well half in the first and half in the second – I had to split it up into two as I didn’t have enough random replacement colours at hand). What I need help with is to finish mapping out what colours have changed (after you replace the MSO.dll file).

You do this by…

A. Visually taking note of colours that have changed.

B. Taking a screenshot, then checking which colour it is (in HEX – I use Photoshop).

C. Add the hex into a spreadsheet which automatically matches the hex to the random colour. The offset is also automatically calculated which will be used to change the colours in the final script.

D. Note down the section, type and item description so that we know what the colour/entry relates to.

Note that finishing off mapping out all the colours (well the main ones at least) will take many hours/days to complete.

If you’re still interested let me know and I’ll send you files/instructions per email (or other preferred method of communication).

Help with this would allow me to focus on finishing of the script/theme-files part of the work.


– Eddie


Ok, I’ve now got a working script that will replace colours at specific offsets (from start of dark theme section). All I need now is a theme in the form of a .csv file with offsets and replacement colours. As I have most of the Outlook parts mapped out already, I will start creating a dark theme based on this info. Once I’m happy with this I will release a beta version of the script and theme for people to try out. Won’t give an ETA for this but this is one of the last pieces of the puzzle. Once I’ve got a theme sorted, I’ll look into mapping out the remaining colours for Word, Excel etc. and create instructions for ppl to create their own themes.

– Eddie


99 thoughts on “Eddie’s Office 2013 Theme Mod

  1. I have downloaded MSO.dll, but it differs greatly in size from from one, installed on my PC.
    That is because I’m using localized version of Office 13, as I think. Is it possible to get kind of “map” of code to replace, so I could try to do it myself?
    Download link of Working.zip seems to be dead. Sorry for my poor english… cheers 🙂

  2. Fyi; The DARK theme was formerly available… These fuckin idiots at Microsoft decided that it was too good for the rest of us PAYING consumers and decided to make it a premium option available only to 365 subscribers. So basically if you are NOT part of that monthly club then the option is RESET every single time you start office. Also; if you set the registry key while the app is running it does not take affect.

    It will force change, and I’ve tested this many many times.

    Set “UI Theme” value to 4. Located here:
    HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\UI Theme
    HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Common\UI Theme

    I paid your office license fee. I have the version desired, why pull this feature???? FUCK YOU MICROSOFT

    • Hi! I wish it worked for me.. but when I start outlook this value is reset to 2 again.. if you know maybe I should turn off some process?

  3. Hello Eddie, I am still not able to download the files that you posted today. Could I provide you my email address to send them to me?

    I also apologize about being a Noob, but could you make a YouTube tutorial on how to install the DLL to make my Office Theme darker? I am more of a visual leaner.

    Thank you,

    • I apologize I am able to download it now (was not able to at my work computer). However, I would still like to know how to install this theme. Do I just go into the C:/Program Files (X86)/Microsoft Office/Office15 folder & just paste it on there?

      Thank you,

    • Yes, simply replace the file (make a backup first), and then restart Outlook or the computer.

      Note that the files posted are now pretty old and most likely won’t work (unless you haven’t patched Office in ages).

      In order to get it working on Office that’s up to date with patches, you would need to download and run the script. I can’t guarantee that it still works as I haven’t used it in ages. For instructions (if not included), see earlier posts below.

      Best of luck!

    • Sorry, Dropbox killed the public folder…

      New links below:

      central.hopto.org/Dropbox/Office 2013 dark theme/MSO.DLL
      central.hopto.org/Dropbox/Office 2013 dark theme/MSO.DLL – 64bit – 2015-04-17.zip
      central.hopto.org/Dropbox/Office 2013 dark theme/Script – specific offsets.zip
      central.hopto.org/Dropbox/Office 2013 dark theme/Working.zip


  4. I am unable to locate any scripts and I LOVE the Color theme you have created, can you please repost the scripts for others to use! Thanks.

    • See below comments for downloadable .mso files. Note that some of those below are for older versions. As others have done in the past, you should be able to modify current .mso files with the files I’ve posted. You could even customise the colours if you wanted to (and want to spend the time).



  5. Hello Eddie, thank you so much for your help 🙂 I want please to know why the file with the dark theme bigger than the original file? Did you decompile the file and recompile it? Thank you again

    • Most likely due to the fact that the .mso files are updated with Office updates and the ones I (and others after me) were created based on older versions of the .mso files.



  6. I am struggling with the very helpful solution to find the correct line in the mso.dll file to modify the dark theme and the white theme. I think that for my purposes, I would use the mso.dll file of the original poster and would rather delete the two unwanted themes in Outlook that I don’t want. Is this possible? And if it is not currently possible, can one of you hackers make it possible? 🙂

    As background, my issue is that Outlook 2013 reverts constantly to the light theme that I hate, when opening a new instance of Outlook. I like the grey theme that has been modified and it would be perfect if Outlook didn’t have any other theme to revert to. Would it be easier to remove the unwanted themes completely? Or to modify the MSO.dll file so that each option only shows the modified colours? If someone can help out with either option, I would be really grateful.

    • Probably easier to find out what’s changing your office to the light theme. Group policy? If so, ask your admins to make it user changeable. If not you might be able to hack your registry if you’ve got admin rights.



  7. Hello,
    After update I finde only 3 files here C:\Program Files (x86)\Common Files\microsoft shared\OFFICE15…. can some one help me please?

  8. Hello,
    It worked for me thanks, but i think since one month microsoft has sent updates and delete the mso.dll file… now i can’t finde it any more… please help me if u can… thank u very much…

    • Fabio it wont have been deleted as office needs it. Are you looking in program files or program files (x86)? Have hidden files and folders view active?

  9. Just downloaded the MSO.DLL and applied it, thank you for your time in figuring this out Eddie. I’m surprised that a few more options didn’t come pre-loaded with the software.

    • I would second this thought, or at leaset a map of what to change in the script to change the different fields would be nice.

  10. This looks like an awesome project. I was wondering if anyone had made progress on the Word theme colors layout? Or is the Outlook one the only one complete? Even any info on which .dll file to start messing with? Again, big thanks to all who have contributed, especially Eddie.

    • Only Outlook was “completed”. Never got around to doing the other parts. Life got in the way so no time on my en to finish this.
      MSO.DLL is the file you want to modify. Read through all comments in this and previous posts in the blog and you should find all the info you need.

      Best of luck!

  11. Thanks Eddie, Script works like a charm. I will work as much as possible but like you said life is on the way. for those that havent been able to change the MSO.dll file I always copy the file to a different directory, press “alt” on the file explorer then go to tools> folder options> View and remove checkmark from “Hide extensions for known file types” then add a .bak to the original MSO (MSO.dll.bak) now you have a backup. now either copy the MSO provided by Eddie or my 32-bit version (MSO.DLL – 32bit – 2015-04-17(ALL CREDITS to EDDIE) https://www.dropbox.com/s/946qgjgl2yxcy5w/MSO.DLL%20-%2032bit%20-%202015-04-17.zip?dl=0 (Link to my 32-bit Version).

    just wanted to share.

    32-bit :go to C:\Program Files (x86)\Common Files\microsoft shared\OFFICE15 >Rename MSOdll to MSO.DLL.bak and replace with the downloaded file.


    • That did the trick! I am a blockhead and likely my biggest issue was the 32-bit versus the 64-bit part. Thank you both for your help and work on this. My eyes are already enjoying this break from the white blizzard…

    • Hello Andres, could you please tell me why your file is bigger than the original file? and why it contanis data which is not in the original file (I mean more data not only replaced colors)

  12. Eddie,

    You are amazing and the retinas of the world thank you. I seem to be having the same issue that others have mentioned where the CSV is not being found by the program. Have you encountered this at all?

  13. You people are utterly amazing for solving this problem. It’s an awful deliberate decision from Microsoft to release a product with such poorly crafted color schemes. It has destroyed my eyes. You guys have finally redeemed this product. Thanks so so much!! I wish Microsoft would pay you for your efforts.

    Thanks again!

  14. Thank you! I found I had to go into safe mode to run the script properly as not matter what I did that MSO.dll file was open. Be prepared if you have epilepsy as the screen will update and flash for about a minute! 😉 Any chance of a few of these scripts to change to a bit lighter theme? This is really really dark. The opposite extreme. 😉 Thank you for the effort!

  15. This looks great – I’m bookmarking this page so I can apply the changes on the remaining components when you have them figured out. Thanks for your efforts & expertise.

    • Sorry don’t get your hopes up as I have even less time now. Perhaps someone else with time to spare can finish it. Otherwise Office 2016 is around the corner from what I understand.

  16. well I’ve tried and tried to use the script but keep getting an error, “The system cannot find the file replacement_colours.csv”. But it is there, it’s in the same folder from where I am running “replace_specific_colours.cmd”. Any ideas? I’ve put the files in a couple different locations but I can’t seem to figure out where this script is looking for the file, if I did I would just put it there.

       This script will patch the MSO.DLL file replacing the dark theme
       with a new darker theme as per replacement_colours.csv
       Make sure you exit all Office apps and wait a minute before continuing
       Press any key to continue . . .
       Using install path from registry:
       C:\Program Files\Microsoft Office 15\Root\VFS\ProgramFilesCommonX64\Microsoft Shared\OFFICE15\
       Checking if MSO.DLL is locked
       OK - MSO.DLL is not locked
       Taking a backup of MSO.DLL
               1 file(s) copied.
       Replacing each colour in the dark theme as specified in replacement_colours.csv
       The system cannot find the file replacement_colours.csv.
       If no errors have popped up, MSO.DLL should have been successfully
       patched. Start any Office app and change to the dark theme to see the changes
       Press any key to continue . . .
  17. Maybe try to swap dll files from Office 2016 version? It has nice themes available. If I only knew which file is responsible for those in Of 2016… 🙂

  18. Hello, i love the work that is being done here, i have so many users that complain about the outlook blahhh theme. quick help i was unable to get the scrip working, it fails saying that it cannot find the string. does anyone know the location of the Group head fill color? this is the only color i need to change right now.

  19. I am forced to move Office 2013 as well from very nice Office 2010 blue looks which is pleasant for eyes, so i would definetely need this hack as i hate this ugly Office 2013 themes.

  20. HEY EDDIE,
    I have very gratefully downloaded this link, and have extracted it to the correct location, but what in Hades do I do after that?
    Thanks for your help dude,

    • That should be it. I assume you renamed your original MSO.dll file before extracting the modified one in the .zip. Start Outlook and select the dark theme. Your colours should be properly dark now.

  21. Hi Eddie,
    Nice job!
    BTW you can simply change to one of the standard Win7 High Contrast themes, and then alter the colors (by clicking Window color button) as you wish (black to dark grey -I use RGB 20 20 20 for window and 3D objects item-, etc). All the Office apps will also change color and even the Windows Explorer. The only handicap is seems like you cannot use Aero when using High Contrast themes 😦
    I also tried to restart using ‘Net Start uxsms’ in Command prompt but did not help.

  22. Hi All,

    Sorry about going underground for a while. Life got in the way 🙂

    Don’t have much time to spend on this for now, but I figured I’ll (finally) share what I currently have.

    For those who only want to try the half-baked dark theme, download the below file, extract it, and run replace_specific_colours.cmd
    This will replace (after backing up of the MSO.DLL first) the dark theme colours for Outlook. Word, Excel etc. have not been done/completed.


    For those who would like to continue and hopefully finalise what I started, feel free to download the below file (255 MB) which is everything in my working directory. Note that the MSO.DLL file changes with Office updates, so the MSO.DLL fiiles in there probably won’t work if you are up to date with Office updates (you will need to create new ones based on your current MSO.DLL version – I kept the files so you understand my workflow). Use the scripts in the two folders to set all colours or specific ones.


    I’ll try to come back and answer questions around this time permitted, but I don’t have time to continue working on this ATM. Maybe this will change in the future.

    Best of luck!


    • Thank you SO MUCH Eddie!!! The script works just perferct 🙂
      Hope your life got into the right way .)

    • What directory should I save this file to in Windows 7 64 bit? The OFFICE15 folder is in C:\Program Files (x86)\Common Files\microsoft shared\OFFICE15, but there is no MSO.DLL file present there to replace.


    • Ah, nevermind. Even though Windows 7 is 64 bit, Outlook is 32 bit (hence being in x86 directory I guess). I would think this means that the mso.dll file would not work.

      Thanks anyway

    • Thanks for getting back to me Eddie.

      Unfortunately that didn’t work. The MSO.dll file was not locked, backup was completed successfully, and then XVI32 ran, but gave this error:

      Error in line number 2:
      FIND E9 ED F1 00 54 54 75 00 E2 E4 E7 00 A7 AB B0 00

      FIND: string not found beginning
      at address $0″

      I also did a Syntax Check, and it said “Syntax check passed without errors”. Not sure what to make of this. Any ideas?


    • Looks like 64-bit and 32-bit versions don’t have the same colour bits in the MSO.dll then. If they are not the same, You would basically have to map out all the colours again (lot of work). If anyone is up to this please go ahead. Unfortunately I don’t have time to get this done. If you share your MSO.dll file, I could have a quick look to see what’s going on.

    • I would share the MSO.dll file, except that I don’t appear to have one by that name. In the directory C:\Program Files (x86)\Common Files\microsoft shared\OFFICE15 there actually is no .dll file, and I’m not sure where the equivalent would live.

      This is probably not worth the effort, but thanks for your help along the way!


  23. Hi Eddie,

    Could you pass on a copy of the MSO? This theme would be ideal for my daily work and I would gladly recommend it to the rest of my office.


  24. Hi Eddie,

    Great effort, I would be happy using whatever you have so far and recommend this mod to the rest of my office if you could pass on a copy of the MSO?

  25. From what I see here it seems that there’s no alpha channel. I’m a little disappointed.

    But I can’t wait for the new themes! Good luck finding the title bar.

  26. Eddie,

    Thanks for all the time you’ve put into this and I hope you or somebody else is still working on the script. If I understand everything correctly, you’re going to use an Excel spreadsheet to enter the HEX colors and then a script will insert those HEX colors into the appropriate locations in the necessary files. One thing I found that might make this a tiny bit easier from the end user perspective would be to allow the user to shade a cell using the color picker and then have Excel automatically generate the HEX color. I’ve been using this macro (http://www.geoplanit.co.uk/?p=659) for some other things I’ve been working on, and I hope you’ll find it useful.

    Keep up the good work and hopefully we will one day have a great tool for theming Office 2013.

  27. I found out that you can change the Theme also through Windows to a certain point.

    Assuming WIndows 7, you can personalize your desktop by right-clicking on it and select Personalize.
    Now select one of the High Contrast Themes. These are for disabled people and therefore by US law, MS needs to use them :-). So when you select one of these themes, Office uses it.
    Select the option Window Color at the bottom and any changes you make here also affect Office 2013.

    Doubt many people like the High Contrast options, but may be it helps with figuring thing out.

    • This parrot is no more. It has ceased to be. It’s expired and gone to meet its maker. This is a late parrot.
      (Change parrot to site)

  28. Our company just updated to Office 2013, and folks are already complaining that the color scheme (or lack there of) not only induces eye-bleeding, but impedes efficiency. These kinds of modifications are, sadly, way beyond any of our abilities…we’ll eagerly be awaiting a script!

  29. Hey guys, this looks like time well spent! I am happy to help out if you need. Have photoshop and hex editor and had a play around with the colours myself… very time consuming indeed! An update to the posts here would be appreciated to know how things are progressing 🙂 Thanks!

  30. Just a thought, any chance of getting this on dropbox or better yet GIthub? I’m sure you can’t put Microsoft’s DLLs there but using python or something else there could be code that patches to the files. So really it would be just a public HEX map with replacements.

  31. I just updated to 2013 and have already started modifying some of MSO.dll to mellow out Outlook’s color scheme. Would it be possible to get a copy of the color map you’ve put together? That would help me out greatly. I’d rather not redo work that’s already been done if possible. Also if I discover additions to the map I’d be happy to re-post it to help further the project. Thanks.

  32. Awesome. That looks great. Have any code to share or file replacements? I’m about to reinstall 2010. This is the first sign of progress I’ve come across. Everything else is people raging about eye strain. I use 2010 at work so I’m good. When I come home to work on an Access project at night my eye’s are screaming. And I already use f.lux to dim my desktop.

    Good job, Eddie. I’ll be following this.

  33. I’d like to volunteer if there is still mapping to be done. I’m no great hand at this sort of work, but I have to do SOMETHING. project JLN at AOL.

  34. Also, instead of using photoshop im using “hex color finder” which is easier than photoshop. Also ive started working on the ribbon color, and its pretty difficult so far. Im using a dissasembler to trace the threads, but not much luck,

  35. Hi eddy, sorry for the delay, I forgot to check back.
    please send me what you have thus far to my email below. I will see if i can figure out the rest of the colors,( ribbon, title, text etc.)

    jfalfy ( a t ) yandex (dot com)

    thanks again!

  36. Hmm…. Tried to replace some hex according to your table, but nothing changed. Save mso.dll worked fine, but no change in colours. I’m running Office 365 ProPlus at work, might they ahve another place to read the mso.dll? Can’t find anything on my local HDD.

  37. We need to find some way to make Office 2013 exempt from assuming the changes made to the desktop theme. Maybe a switch in the registry or something.

  38. Any chance of getting a copy of the map you put together? I have been playing it too and just going off your screen shot from yesterday some of the things I have done and got to work arent matching up.

  39. Ok, I’ve got some good news and some bad news.
    The good news is that I’ve got a first rough initial version of a dark theme (only Outlook colours changed for now).
    The bad news is that I haven’t been able to change all colours that I would like. In the screenshot below, I’ve change all the colours that I’ve been able to find to pink. I also changed the system colours to see what was ruled by these.

    As you can see I haven’t managed to change the colours of:
    – The titlebar background
    – Ribbon background
    – Email pane text (update: I believe this is ruled by conditional formatting within Outlook)
    – Scroll-buttons/bars

    I’m hoping I will find these colours somewhere in the MSO.dll

    Anyhow, below is a teaser of how the dark theme will look like. It’s an early version but it gives you an idea what I’m aiming for.

    Also, I’ve got a nice workflow of how to create a theme so it should be fairly easy for anyone to make their own eventually.

    • Hi Eddie.
      I really admire your affort. Please let us know how could we appreciate it with some donation .))
      Could you please release your dark “teaser” MSO.dll in advance?

    • Hello Eddie, thank you very much 🙂 I want just to know please if you have decompile the file… because whene I compare it with the original… it seems that the new file contains more than the original (not only replaced colors)

    • The bright white theme is horrible and the light/dark grey is not much better.
      I still can’t believe there isn’t an official theme editor for Outlook but you are almost there! Great work on these mods so far! I am starting to see again! 😀

      Did you make any progress to modify (fix) the reading pane section to that we get rid of that last bit of white? I also notice there is a bit of blue left over…not sure if that was intentional?

      Thanks again for helping save our eyes….and the planet! (try and figure out the energy usage of millions on PC’s running bright white Outlook on their monitors!!)

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