First you need to understand the domain, then you can automate it: http://en.wikipedia.org/wiki/Color_theory http://en.wikipedia.org/wiki/Color_theory Another

First you need to understand the domain, then you can automate it: http://en.wikipedia.org/wiki/Color_theory http://en.wikipedia.org/wiki/Color_theory Another challenge is what is it you want to achieve? Do you want people to say "ah, nice", or do you want them to "react" (click something for instance). Those two may be mutually exclusive in some instances, as generations of neon signage, "sales" banners and similar are living proof of.