I have asked myself this question many times. living in South Africa I have seen both sides of the coin.
The apartheid government was anti anyone white and had segregation. Basically whites lived in white areas, Indians in another and blacks further away. We all know it is wrong as it builds hatred and resentment.
Today 24 years after a black government took power we have similar issues but in reverse. This doesn't make sense and the only answer I can think of is this. The children growing up not seeing color are because of their parents. The hatred is being bought forward by the next generation by the old generation.
This will hopefully phase out at some point but could take generations. It is sick and sad but it is the reality. The other parts of the world are different though but similar.
In America and Europe parenting and peer pressure could change your thoughts. If you are educated and have the right upbringing with no influences you will have no prejudices towards other skin colors.
The racism I see more and more of though is blacks hating whites blaming them for their economic situation. The more black families that educate their children and better themselves the better and one day I am hoping that racism will be very rare.