KDE doesn’t look that great on Mac. And since I use Krita a lot these days, I have taken the time to put together a dark theme to make it looks a bit nicer. Feel free to modify it to your liking. Right click on the file and save it to your computer. Put it inside this folder: ~/Library/Application Support/krita/color-schemes
If you want a darker selection, look for 106,107,134 and replace it with: 70,70,77. This is so the window bar doesn’t stand out when Krita is in “Subwindows” mode. There doesn’t seem to be anyway to change just the color for the window’s title bar. You either change all, which affects the selection. When choosing a selection color for the theme, I avoid the color that is available for the Layer’s color.