Add an Automated Complementary Color System for Text

[jrg94]

Right now, the automated primary color detection of logos ignores the reality that some logos are light colored. This clashes with the white text. It would be nice to be able to anticipate this automatically and select a color that would look good against a light color.

Part of my wants to just computer a complementary color and use that, but that would completely change the way my current images look. Perhaps we could instead use some black vs. white algorithm to select text color. Alternatively, (though this wouldn't work for me) we could extract a secondary color from the logo and use that.