Never was a fan of recolors, but maybe making armors that look similar to each other would be better for your idea. For example:
Dark Robes (black) would just be for show, so they'd stay the same as they are in the game.
Dark Robes (red) would have some extra armor, maybe a metal shoulder-piece to represent that it will give you more STR and HP.
Dark Robes (blue) would have less clothing, to give you a 'faster movement' type of feel, and you get more AGI or EVA.
Stuff like that would (imo) work better. But I do very much like the idea of stat changes depending on the color of the armor.
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"Nurd, you're like a fucking swiss army knife" - Necrosis