Oh, and calling Ctrl::SetDarkThemeEnabled() with Windows set to light theme causes problems both in TheIDE and test app. Calling Ctrl::ReSkin() after fixes these problems but now the theme is white.

Chameleon really needs to read and write themes once, respect what you tell it to do and have a clear point after which you can make changes that are never lost by random CtrlCore behavior.

Calling SetDarkThemeEnabled once in GUI_APP_MAIN should be enough for that application to be dark forever. Then you should be able to change ink from black to Color(51, 51, 51) and this change to be respected forever.