dd2 was able to name some colours before she 2, although when the HV came to do her check up she refused point blank to say any even though she knew them.
I remember when we were at the aquarium in St Andrews last summer there was a play area with a lego type of wall game and she pointed to all the coloured bricks and named them all, even the black and purple ones, I was impressed as I didn't think she knew those two.
A funny thing she does is refers to the bedrooms in my granny's house by colour. One is the purple room as it's painted purple, well lilac, and the other is the yellow room as it has a yellow duvet cover. Makes perfect sense but we call them by other names but she refuses and calls them by their colours.