[@sMoKe] The use of alternate colors has always been a thing in Digimon, Agumon, for example, boy if i had a nickle for all the variants that Agumon and his evolutions went through, i'd be rich. Agumon, BlackAgumon, SnowAgumon, Agumon 2006, BlackAgumon 2006, Agumon Hakase, Agumon X, just to name a few.
My point is, if you wish to use a vairied version of a Digimon, go ahead, as long as the colors look good with what you're going for.  (also it's a common theme that Digimon are Data IRL and IDL, so we'll go with digital and not organic)

[url=http://i.imgur.com/Y7ixVAv.png]This[/url] would be a good example of what to do
[url=http://i.imgur.com/Zm08xDG.png]This[/url] would be a good example of what not to do

As for evolution lines, i typically do factor personality after the evolution line has been decided, since i don't see the two as needing to correspond. Everything is still in the beta, and we wont start before everyone is certain as to what they want.