SUMMARY On Manual available ColorScheme-ViewBackground, but this class not support on Plasma Theme and not applied. STEPS TO REPRODUCE 1. open any widget with CSS Color Support, for example panel-background.svgz replace all class="ColorScheme-Background" to class="ColorScheme-ViewBackground" 2. restart plasma theme with clear cache 3. result - ColorScheme-ViewBackground not applied!!!
for ColorScheme-ViewBackground applied color from ColorScheme-ButtonBackground. It's bug
Some context: https://github.com/PapirusDevelopmentTeam/materia-kde/issues/66#issuecomment-633637239
Anybody can confirm & fix this bug?