Darker Office 2013 Theme Hacks


You want an Office 2013 theme that is EASY on the eyes? Is that so hard to ask??

http://twitter.com/OfficeThemeHack )

A writer needs something comfortable to look at. Visually relaxing.  We are behind this app for many many hours.

Suppose… there was a way you can fix the Office 2013 theme to look similar?

Certainly NOT using the Office configurations. You only have 3 choices. Thats it. Look up all ‘how-to’ blogs you want, but it’s still going to come down to those same 3 annoying options.

Solution? Hack the files. It’s probably going to come down to an .XML or .DLL file. It will be some benign setting, or color hash. Question is… Finding it. I will checkout this stuff, and see what I can see.

If I find anything ( or if you do ) please comment on this site. We ALL need to know how to do it.

Once we find out; I’ll take the liberty of writing up a custom ‘how-to’ on hacking the Office 2013 themes. I might even supply the .xml, or .dll files to make it quick and easy.


72 thoughts on “Darker Office 2013 Theme Hacks

  1. Hello,
    I thought this would be a good place to post this. I have a solution that allows you to create your own custom themes. It is the first ever custom UI theme add-in called S-themer that I have been developing over the last three years. It’s for Microsoft Office 2007, 2010, 2013, 2016/365 for Windows.


    It hasn’t launched yet but from the website you can see how much of the UI is covered by S-themer (spoiler: it’s actually more than what is changed when you switch between the default themes). You will also find a signup form for a newsletter to stay up-to-date and a contact link for any questions.

    Steven Kendrick
    Creator of S-themer for Office

  2. Hey Eddie, I’ve been using your MSO.dll for over a year now, and it still works for the most part! It looks like the last update or two from MS has changed something and the minimize icon is now an X. Not sure if that can be fixed??

  3. Wow great topic to help us to “deasawfull” those horrible themes made by a drunker Microsoft guy, don’t have other solution.

    BUT, i found many colors by help me with the working.zip file but not the background in the white theme. Could you help me and answer me the HEX code for this background et if i can change all HEX or just someone on the MSO.DLL file?

    Thanks a lot

    • I belive what your’re looking for can be found in combine.xls, outlook tab, row 59.



  4. Is there a dll to download at this point? I’ve read over everything, but it looks like I’ll have to customize manually. Either way great work!

  5. I just got invited to run Office 2016 and guess what, black is back! The dark theme is really dark! Color options include Colorful, Light Grey, Medium Grey, Dark Grey (dark theme in office 2010) and our favorite, White (as in burn your retina).

    • Do you know if there is a way we can take some files from the 2016 version, and simply copy them into a former version?

    • As mentioned by officethemehacker previously, checkout the front page for my unfinished mod. In the comments of that post you will link to a zip archive with a script for modifying your dark theme colours. This works for 64-bit Office 2013. For anyone keen, there are also the “source” files for anyone wanting to continue/complete the work.

  6. HI officethemehacker, did you give up on that office 2013 issue? I would like to know if you have found a final solution to changing at least some of the base colors in outlook 2013?

  7. Hi Eddie… You’ve provided an excellent contribution to this effort. With your permission I would like to take a collection of your comments, and create a full page post about them. Feedback can be followed directly under comments within that post. What say you?

    • Hi officethemehacker,

      Sure thing, go ahead. It might be easier than to keep replying to the one post 🙂
      I’m hoping to have something ready for consumption real soon.

      Btw great job on setting up this blog as it’s the reason I finally got around trying to sort this out.


  8. 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°”

    3. 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.



    • I’ve made some progress and it’s just a matter of time before I’ve got it all mapped out. I’m hoping I will have something in a week’s time. If someone out there would be keen on throwing some code together, please let me know.

    • Almost done with mapping out all the colours. End result of this will be a script anyone can run to apply a theme (mine or your own). ETA is one week

    • 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.

    • Hi Eddie, its Jan 13 2015 and i wanted to know what your progress was on the script? Did you stop because you found out there will be a dark theme in office 16? 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!

    • 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 visually taking note of colours that have changed, taking a screenshot, then checking which colour it is (in HEX – I use Photoshop), and then 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. You need to 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.


    • 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 ppl 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.

  9. you can change the background color along with other settings (i.e. text color, highlighted text color, button, inactive windows color etc via high contrast theme settings-tested in windows 8.1. choose a HCT (one of four)–>click on Color (High Contrast). Now you can change the colors. not the best solution but works.

    • Obviously you don’t own the program. There is no option anymore to change the background. It is gone with the latest versions. The only options now are Snowblind White, Communist Gray, and Gulag Gray. That’s it.

    • You had me at “Gulag Gray”.
      Thats about how it makes you feel to work on it day-in and day-out. We need to escape from these colors badly.

  10. I keep thinking I have something, but then as I scroll down I see someone else has thought of it. So far no father than the rest of you with this, but I’ll ask around at work. I work with some super talented programmers who may be able to do some messing around.

  11. I don’t suppose it’s simply a matter of modifying the files, and dropping the mod files plus the teleric dll’s into the Office folder? C:\Program Files\Microsoft Office 15\root\office15

    Cause… you know… problem solved if thats the case 🙂

  12. Yeah; The Telerik tool set.
    It’s true that RadCrontrols will certainly get you there. Checkout the Style Manager for basic sets.
    All you need are the .dll’s

    Currently Telerik RadControls support the following themes:

    Office Black – this is the default theme. No assembly is required for it.
    Office Blue – requires Telerik.Windows.Themes.Office_Blue.dll.
    Office Silver – requires Telerik.Windows.Themes.Office_Silver.dll.
    Expression Dark – requires Telerik.Windows.Themes.Expression_Dark.dll.
    Summer – requires Telerik.Windows.Themes.Summer.dll.
    Vista – requires Telerik.Windows.Themes.Vista.dll.
    Windows 7 – requires Telerik.Windows.Themes.Windows7.dll.
    Transparent – requires Telerik.Windows.Themes.Transparent.dll
    Windows8 – requires Telerik.Windows.Themes.Windows8.dll
    Windows8Touch – requires Telerik.Windows.Themes.Windows8Touch.dll
    Metro (obsolete) – requires Telerik.Windows.Themes.Metro.dll. Should be replaced with Windows8 theme.

    • Actually I just downloaded, and tried to browse for files I could open. Inside the tool most if not all files have “(not supported)” next to them, and they can’t be opened with dotpeek. There are maybe a few under the Office15 path that can be opened. I don’t see any color code data in there. The few files that can be opened by dotpeek have this next to them “(, msil, .Net Framework v4.0)”. It’s a good tool, but maybe not the one we need. Or… most of the .dll files are encrypted, and doesn’t permit them to be opened.

      I would try another tool to see if you get better results. Maybe PE Explorer? http://www.heaventools.com/overview.htm

    • Definitely; Just downloaded the PE Explorer and so far works great on just about all .DLL files.
      You can find it here: http://www.pe-explorer.com/

      When you get to tool, just open the .DLL you want with the usual ( right-click Open With ), and when it opens you’ll see the file source info immediately. All you need to do is click on the quad-colored icon in the tool bar. It’s the Resource Viewer. Once you do that you can see the ‘search’ option. All you need to do is look for the color codes you want to modify.

      Here are those awful grey, and white colors found in Office 2013. Man… they really suck.

      FFF1F1F1 = F1F1F1 See it here: http://www.colorhexa.com/f1f1f1
      FFE5E5E5 = E5E5E5 See it here: http://www.colorhexa.com/e5e5e5
      FFFAFAFA = FAFAFA See it here: http://www.colorhexa.com/fafafa
      FFF3F3F3 = F3F3F3 See it here: http://www.colorhexa.com/f3f3f3
      FFE1E1E1 = E1E1E1 See it here: http://www.colorhexa.com/e1e1e1
      FFC6C6C6 = C6C6C6 See it here: http://www.colorhexa.com/c6c6c6
      FFD4D4D4 = D4D4D4 See it here: http://www.colorhexa.com/d4d4d4
      FFABABAB = ABABAB See it here: http://www.colorhexa.com/ababab

      Any way; you can replace them with something new, and then I guess recompile, and open word. If you see your new colors applied, then your changes have been successful. There ‘may’ be some kind of encryption on the .dll’s or something that might cause problems with saving. Doesn’t hurt to try though.

  13. You would need to have an application that monitors file changes while the Office 2013 installation was being carried out. The monitoring app would show you a report of all files, and registry entries added or modified. The report or “log” will be quite large, but will definitely display everything that was done.

    This would give you a massive amount of information, and it would take some time to analyze all the info. Usually in Application development the color configs are by in large located within a color hash code ( or series of codes ) located in a DLL some place. Traditionally those DLL’s are compiled, and will probably have some kind of compression, or encryption on them. They’ll need to be decompiled, and some the configs would need to be played with, the file saved, and the application opened to see if there was any change. Not outside the realm of possibility. I’ve done it before on other apps.

    There’s a number of decompilers out there that will allow you to dissect one, or a series of DLL’s. I would just google it for the right tools.

  14. I was wondering if it would be possible to identify the relevant files and registry entries by checking a system with the preview version installed compared to a system with the full version installed. I know that the theme options were not in the preview. unfortunately I am not techie enough for the job nor do I have both versions. I hope my suggestion is helpful in someway.

  15. I was able to decompile and generate these files, I don’t know if anyone will find these useful or not but everything is from


    so without further delay;


    If someone is able to get something going with this, that would be great, thank you.


    • Hey b3ck, were you able to open the encryption? So far I got gibberish. Manual decrypting is so numbing.

  16. Hi OfficeThemeHacker,

    The file you are trying to locate is the System.Windows.Controls.Theming.Toolkit.dll zipped located in C:\Program Files\Microsoft Office\Office15.

    It requires a license for you to open the encrypted data because of MS Silverlight.

    I’ll try to dissect it manually and see how far I go.

  17. I FOUND A SOLUTION!!!!!!!………kinda, much farther than anyone else ive seen on the internet. maybe it will help someone more tech savvy than myself, ok i know your like what is the solution by now. all you need to do is go to this link and fill out a servery , im kidding, turn on the high contrast theme for windows and now its black, even the ribbon changes and everything works perfect. however colors will be different so if your doing something that requires accurate colors you need to check to make sure the colors are right. the colors will display as yellow/purple/green whatever your accent color is but the settings in the program still work. if you highlight something and change the color it will change it, it just will not display the change in HC mode if that makes sense. now for you smart people, idk if there is a way to enable high contrast mode in one application at a time without ruining your whole theme and returning to windows classic every time your working. or if you can figure out how it works now that you do have a way to change it through this method. i’m sure this gives some better clues about what is going on with it than hunting around in registry keys…….but post here with any updates as usual. to anyone who happens along this site i hope this is a viable solution and the fight is not over, we cant stand for a eye searing brightness that poses as “dark grey” when we’re on our 5th cup of coffee and its 3am….ok bye, good luck to all

  18. Captured the registry calls when theme is being changed from Office app
    This was the registry key that caught my scan

    There are two keys in there
    HKCU\Software\Microsoft\Office\15.0\Common\UI Theme

    These map to the theme and UI color scheme in office app
    For color scheme, the DWORD value for UI Theme is 0, 1 and 2 respectively
    These map to White, Light Gray and Dark Gray
    Some where there must be a palette setting for these three color schemes

    • The other related key of interest would be
      Has this value for my Outlook configuration
      REG_DWORD, Length: 4, Data: 15781287

    • This setting does not refer to the general theme, but you’re kinda on the right track. Following your lead, I checked out the reg entry you named. “15781287” is the decimal equivalent of the hexadecimal “0x00f0cda7” or just “f0cda7”. Further digging on this result provided this insight… http://www.colorhexa.com/f0cda7 Note the color….baby$h!t orangey-brown. This color is nowhere to be found in the 3 general Outlook themes. Seems to have something to do with a View Selection as the regkey indicates (go figure). Only objects on the VIEW menu of this color are the “bell” icon (Reminders Window) in 3rd position from the far right of the ribbon. Also the informational “triangle + !” symbol indicating a Send/Receive error at the very bottom underneath the “mail”, “calendar”, etc shortcuts. And, I guess, to some minimal degree in the “Categorize” tags option (the 6-paneled color palette icon) of the HOME menu and “Categories” sorting option of the VIEW menu. (I’m kinda guessing with those, however, because they’re small are hard to make out. but very close, if not exact)

      …experimenting………. Ok, I just spent the past few minutes experimenting with this value. Changing it doesn’t appear to have made a difference. If you click the small color box next to a hex color value in the Search field at the top of the page on the URL I provided, it brings up a palette. You can choose whatever color you like here to identify its corresponding value. I picked something soothing in the blue range and copied the hex value to the regkey, saved it, closed/re-opened Outlook. result: NO CHANGE. …at least not that I could tell. Also, the regkey change does NOT save. Changing it, then closing regedit, then re-opening regedit displays the new value, but if you click on the value again as though you’re going to make another change, it reverts to the original, default value (baby$h!t orangey-brown, or “f0cda7”). So that was fun, but unproductive.

      but it’s something akin to this that I think we’re looking for. something that can be changed according to a proper color palette that would be suitable to each user (until Microsoft eventually….maybe….fixes this problem and makes it simple to change in the Options GUI)

      Aegues may be onto something though. While my additional info to an already-discovered tip was fun to play with it clearly yielded no perceptible results.

      – onward!

  19. To help further the cause…
    There are a couple of Reg Keys that are of interest:

    hold the theme number you just set. The 1170 appears to be the important part.

    HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Common\IU Theme
    Also hold the data, but changing does not effect Office; it will get overwritten when reopening.

  20. Thanks so much for this post! I hope you hack the color back into this product. Here’s a tip. If you plan on looking at the core files… Try this path. C:\Program Files\Microsoft Office 15\root\office15

    There is also an older x86 location, but lets begin with whats new so use the newly
    provided paths to start with. Good Luck, and thanks again!

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