Is there a way to force regedit and task manager to use dark theme in W10?

Question

When using dark theme in Windows 10 and in browser on almost all sites, its extremely annoying that when occasionally you need to pop up Task Manager or regedit it breaks all the dark immersion. Is there a way to change this by modifying some DLLs, perhaps?

Answer 1

I can't believe that 2 months actually passed since I embarked on the quest to make Windows 10 100% Dark Mode, in every window in the system. I was focused on this all this time, almost all day long. I went on a few tangents, however, like learning a bit of assembly and injection into other processes, a bit of JavaScript/CSS to style Firefox too, made custom low level API registry access library, etc.

Well, now I can give myself and others a definitive answer of how to do it. At first I thought it's not possible, but it is. And it probably will look better than Windows 11. This is only possible with theme patch, however. It is not possible to achieve adequate Dark Mode on unpatched system, I'm afraid (there is one attempt at this, using high-contrast theme, but due to very poor Microsoft's High Contrast implementation, its very limited and almost unusable). So here is the steps:

1. Use this guide as your baseline.
2. I used BIB3 theme, you can browse Deviantart or other resources for any dark theme you want, but BIB3 seems to work great for my goal of total Dark Mode.
3. BIB3 is not perfect, though. There was major issues with messed up minimise/maximise/close buttons. Also one major bug was that Control Panel and some few other places had nasty white patches in them. I fixed all this problems myself. As you can imagine, this took huge amount of time as I had 0 experience with theaming Windows and also general lack of documentation and information online.
4. It's very important to install OldNewExplorer (you can find a link in the guide). As this program, combined with my theme fixes, removes the Control Panel bugs.
5. Your browser title bar and/or buttons will get messed up by the custom theme. To fix this, you can use this guide. For Chromium based browsers it works fine, but for Firefox I found the solution lacking. So here is my custom userChrome.css code where I implemented a perfect titlebar buttons.

Of course, me being crazy perfectionist, I went on the Windows 10 improvement spree along with the Dark Mode, like removing useless context menu items for Explorer, adding useful context items, making custom garbage collector for Trash Bin, etc. But this all things are out of the scope of this question.

The result:

Note that Task Manager is incorrectly scaled by Windows (DPI system aware), as I changed DPI scaling in the very beginning of this "quest" and didn't restart PC for 62 days and 22 hours +

I hope that my efforts will benefit not only me, but maybe someone else who dreamed about proper Windows 10 Dark Mode, as much as me.

Answer 2

I am looking for an answer without change the theme.

You can use AutoHotKey script to Invert window colors. It will need UI Access.
There are More discussion in Chinese here.

WindowTop has a dark mode feature that can make a window dark, but it only invert the color. The result doesn't look great and it's not smooth and a bit laggy. To dark mode task manager, it will need admin permission.

WindowTop also has a opacity mode. I use opacity 50% as a dark mode alternative since my wallpaper is pure dark. Different from dark mode, the opacity mode is smooth. But to achieve this, a better way is to use this AutoHotkey script.

NegativeScreen can invert all screens color. Different from WindowTop, it has many invert modes. The result can be a little bit better than WindowTop's dark mode. But it cannot invert only a specific window or screen, it can only invert all screens.