Some widgets allow configuring background colors. When a widget presents a textual data on such background, the text color only depends on the current theme, and not the actual background. So, on light themes the text color will be dark and vice versa.

This strictly limits the "good enogh" colors which perform well on different themes. As well as it produces unpredictable results (when users use diffrerent themes).

Let's implement automatic color selection (either light or dark) when a custom configured background is used.