While color coding can get out of hand, a SLIGHT use of it wouldnt be terrible. For example, in north america we have Black, Brown, and Polar Bears...almost identical except for color, size, and lethality. People can and have in real life fought off black bears unarmed, but I havent heard of it happening often with the other two species. Too much color scaling would be silly, though, and not all creatures need color scaling, IMHO.
That said, the main way I would like to see foxes tweaked is making them slightly weaker in the first 3 rings...as it stands, someone who has sunk about 1000 points (which is a lot at the beginning) into learning to use a sword still cant kill a basic fox in ring 0. It would be nice if there were a slightly earlier reward for taking weapon skills.
Im not saying make all foxes weaker. The ones out by mordor are just fine. And that is coming from a resident of Bottleneck.