Turn dark colors into light colors and the other way around.

This is meant to make color schemes that work on a dark background usable on a light background (and the other way around).

Notice that this doesn’t swap foreground and background like “reverse” does. It turns light green into dark green and the other way around. Foreground and background colors are considered individually.

Also notice that when <reverse> is used somewhere and no colors are given in particular (like what is the default for the bottom toolbar), then this doesn’t change anything. This is what makes sense, because when the ‘default’ color is chosen, it’s what works best for the terminal, and reverse works good with that.