Reformat / minimize some color-related math

[HalfWhitt]

I saw a thing my brain couldn't parse. Reasonable people adjust to the world, unreasonable people make the world adjust to them, I'm unreasonable, etc. etc.

PR Checklist:

• All new features have been tested
• All new features have been documented
• I have read the CONTRIBUTING.md file
• I will abide by the code of conduct

[HalfWhitt]

I've been eyeing the color() parsing logic too — and I think it's hiding some bugs — but I think I want to wait on that till 3.9 goes away and I can potentially use match / case.