Build Colors from Colors with CSS Relative Color Syntax (calebhearth.com)

We -- technical people anyway -- usually associate a given color with a particular frequency of light. But I read somewhere that the color brown results from the addition of two (or more?) frequencies of light. Is that true?

Not on topic at all, but crazy coincidence to get so many “c” words on my left hand side: https://imgur.com/a/thwKg0b

I’m not sure justified text works well here, lots of “rivers” through the text.