My first issue is this; Imperials, i.e. whites had serious bonuses to their intelligence and personality, while redguards had some "rage" bonus, like a gorilla, while having bonuses to strength. This is the typical "blacks are stupid but strong" stereotype.
My second proof of this racism is the facial features of the races. Every beast race seem to have african-native features.
Take a close look at this picture http://1.bp.blogspot.com/-jV43kLnu5z0/TbqtU6AJ3jI/AAAAAAAAABY/H-TancWQgDQ/s1600/skyrim_khajiit.jpg
You clearly see features of African animals (panthers, lions, gorillas etc.), which is an obvious reference to blacks. And, as we all know that Khajits are stupid I think this is another hidden racist insult.
http://www.gamemunition.com/wp-content/uploads/2011/04/Skyrim-Screenshot-01.jpg Here we see obvious gorilla-features and references to black stereotypes (like the haircut).