Which colour do you think should be default?
IMO, It was a horrible mistake to change it. Famicom R.O.B. looks so much better then the Grey one, and since it was the default in Brawl, it should've been the default again.
They grey one is just to dull, and honestly ugly compared to the Red one (especially on the 3DS).
But what do you think? Did Nintendo make a mistake when localizing these games?