Top layer of drywall peeled off, showing cardboard

I tried to hang a mirror on the wall and it turned out to be too heavy for the sticky back it came with (which was designed to "pull and peel" .. seemed like a good idea at the time.) When it fell it pulled off the top layer of drywall in a few places. It looks awful. How can I fix this? It's in a rented apartment room. The walls here are off-white. I realize it won't match completely, but is there a repair material that (a) won't be too obvious and (b) is not pure white?