Created attachment 186284 [details] screenshot I use a color palette where QPalette::Window is dark and QPalette::Base is light. this breaks plasma-systemmonitor (see screenshot) as plasma-systemmonitor uses QPalette::WindowText with QPalette::Base and QPalette::Text with QPalette::Window which is wrong.
Do you see this in any other KDE apps too? For example Discover, System Settings, Spectacle, or Filelight?
No, while there are some occasional mistakes in other apps where the qpalatte provided colors are used incorrectly only plasma-systemmonitor is fully broken.
System Monitor itself doesn't really specify many colors, the colors that are showing up wrong are provided by Kirigami and are using Kirigami's View background and text color. If I change the color scheme to have view colors that are inverted from the window colors, things work fine and the cards will use a black background with white text. To me it sounds like you're not using the KDE platform integration, especially because KColorScheme has no concept of "base". Regardless, this is not a System Monitor bug as System Monitor does not touch the colors of these elements.