Are CSS Variables for all themes available?

Modals in my plugin use the inverse them color scheme — if the scheme is light, the modal is dark and vice versa. Looking at the official list of available CSS variables, it seems to be possible to get colors related to the current color scheme, but are there variables for all of the themes available? I imagine there aren’t inverse variables but if I can access any of them, I could at least do the logic of picking the opposite text and background color based on the current theme.

The alternative is to just do a bunch of color picker work, but I’d rather use built-ins if they exist for future proofing.

Thanks for your help.

cross-reference necropost: to any future person who’s interested in this, check out my reply to a similar question.