My terminal has non-default long-battle-tested background and foreground colors, and I barely pay an attention to the entire palette, so coloring works like acid. Some colors are simply incompatible, so tuning them is meaningless. Imagine e.g. any dark blue on medium grey.

What I think would be good (for me at least) is not colors, but sort of markup, like bold or underline, which is available in terminal as seen in man pages and PS1. I usually make them bold and compatible colored.