Your suggestion of comparing opposite changes is an interesting one although there is the more fundamental question of knowing that something is “too yellow” in the first place.

I wonder if perhaps I’ve come up against the limits of auto-didaction. Close, accurate color perception is best [perhaps only?] learned in close contact with an expert, like learning an instrument; practicing a lot and getting frequent, corrective feedback.

Per Wesley’s point, I can and do play with the color sliders but I lack the vocabulary to articulate what I’m seeing. I can see that the colors shift but can’t say why or how.

I can’t wait to see your book — congratulations, and keep us all posted on its progress.