[@Windicator]	In reality, art terms aren't very hard to understand if you're really trying, so i can understand what you mean when you say Secondary Colors (the term Secondary Colors actually means to mix two Primary Colors, just so you know)
Accent is a better term in general to use when referring to the side colors, bringing the original color a new blend with side colors.
Yellow and darker colors like Purple, Black, and Dark Grey work fine, as long as you can mix them appealingly.

	On a side note about Evolution, i will state that there is a basic ruling as to defeat and reverting
If a Champion Digimon is defeated, they revert back to their Rookie form. 
If a Ultimate Digimon is defeated, they revert back to their InTraining form, 
and as followed, if a Mega Digimon is defeated, they revert back to their Fresh form. 
This can fluctuate as the power of the Digimon increase over time, but as it stands this is the set rules when it comes to being defeated.