In the current design, there is no way to get an inverted of custom color when the theme changed.
for example I have custom Black color with code: #000 in light background.
I want the color to change from Black to White in dark background.
but since it is a custom color, the color stay as Black.
an upgraded version of this request is:
how to detect if the background is dark or light?
for example I have 2 logos (images) for each dark and light background, named logo W (for light bg) and logo B (for dark bg)
I want the logos to be placed accordingly, so I need to check if the background is light, then use logo W.
if the background is dark, then use logo B