I can't tell what colour he is due to the picture being so grainy, I have a few ideas running around
Going by the description you have given I would guess at agouti or sable
As for breed he looks like a generic cross breed to me, but as he is a baby he will develop. He looks nothing like a wildie to me.
I will say that 6 weeks is far, far too young for him to be weaned. He should be with his siblings and mum for 8 weeks minimum (some larger breeds shouldn't be rehomed before 12-14 weeks old) and as you say you bought him from a pet shop they are actually breaking the terms of their licence :thumbdown:
You will need to keep a very, very close eye on him, I would be getting some Cimicat (kitten replacement mik) and goats milk (full fat) to supplement him for a couple of weeks to try to help him along.
Make sure you keep him on exactly the same food that the pet shop had him on until he is at least 12 weeks old (14 weeks would probably be better) and NO veg, but lots and lots of hay because kits are susceptible to bloat after weaning and as he has been weaned far too young then he is at very high risk. If he stops eating at any stage then I can't stress how important it is to get him to a rabbit savvy vet as soon as physically possible, because bloat is a killer and the sooner the rabbit receives vet treatment the better chance they have of survival.