How do you name "theme" level resources?

This would have been a social media post, but it quickly became too long.

If you have some software that:

a) Has a specific color (or colors) that is (are) used for branding reasons.

b) Adjusts to "light" and "dark" themes.

I have some questions:

• What do you call that (those) color(s)? 
• Do you have different versions of those colors for when in a dark or light theme? And if so, how do you name them?

I've seen lots of variations in the ways the above are answered, but no consensus.