Color Scheme

Theme is managing Light/Dark background from Color Scheme tab, So it seems as Color scheme has been made for Background color. But, 3rd Option-Custom color is not applicable to Background color, it is working as Font color.
https://prnt.sc/h4s2xw

If so, then caption should be as “Font Color” and Not as “Custom”