I don't know about naysayers. There are those who would say, "Who sees your character but you?" or "Why differentiate your character in a single player non online game"
However, there is no game related reason why one should not be able to tint or change the armor other than the save or game files getting even bigger than they are. How much bigger is the question, but I doubt it would be more than a 10 or 20 MB of game files to create this. Save files would probably not get too much bigger.
Save file size WOULD be the more reasonable point for anyone to oppose it.
But being the pessimist that I am, I just figured people would be all like "PFEH! U WANNA COLOR UR hardcoe DAEDRIC ARMR ANOTHR COLR OTHER THN BLACK??! BLACK IS TEH COOLEST EVIL COLOR EVAR."
Or the next one in line, "Skyrim is supposed to be realistic. Even though it's in a fantasy setting..."
Hey, dammit. Fable III painted armor. I want to paint armor.