I see where you're coming from. Pink is an easy color code for girly and feminine, which even with Holly's "corruption," she still very much is at this point in the story. So while I like the outfit on the right better to represent Holly's growth and confidence in herself, I think a yellow or maybe light purple could still get across the same feeling as pink without it being the obvious color.Damn it would be cool to see Holly with her hair down, it really suits her.
As for the two versions of Holly, Eva is too fond of pink. Even though I have mostly corrupt Holly in most of the routes, I like the one on the left more (I hate pink).