I was going to comment that HSL/HSV can be useful for generating colors that work well, but... the real problem is not luminance as much as the HSL values we co

I was going to comment that HSL/HSV can be useful for generating colors that work well, but... the real problem is not luminance as much as the HSL values we commonly use. See http://en.wikipedia.org/wiki/HSL_and_HSV#Disadvantages http://en.wikipedia.org/wiki/HSL_and_HSV#Disadvantages where CIELAB L* is shown as a better representation. Though it's not perfectly matched to the human eye even so.