So you're saying that skin color is a bigger factor in failed (or difficult) societal integration than cultural perception is?
GTFO. None of your links seem to substantiate that claim whatsoever.
The only reason skin color matters is because it's often associated with a particular culture.
Nobody sees a black guy and says, "Ew. I hate black skin, and therefore reject this individual. He doesn't have the same skin color as me or my friends. He sticks out." This doesn't even happen on a subconscious level.
If anything, it's - "Oh, there's a black guy." If you associate black skin with an aggressive, violent, and anti-social culture, you're going to pre-judge the individual based on your perception of the CULTURE his skin color is attached to.
It's all about culture, bro. Skin color just makes it easy to estimate someone's cultural affiliation.