I´m sorry...tacky?
The natural coloration of a species is tacky? I´m shocked O_O I find that to be an extremely weird affirmation, specially when confronted with the idea that a leucistic one or any other mutation could be seen as less tacky. I don´t mean to be rude, i´m just genuinely surprised to read this.
In regard to your question, there is no such thing as a "best" axolotl coloration. However, from a genetic point of view, all mutants are definitely inferior as they represent a diluted and modified version of the original species. If you want an A.mexicanum, then the best is definitely a wild type with genetic guarantee (good luck finding those....). If you just want a pet, then any of the commercial aberrants is perfectly good, none of them being any better than the others.
I realize my post can be seen as a bit agressive, please realize that it is not my intention.