Children and the color of their skin? Should it really matter at such a young age? Should it matter at all??

At what age do children really notice the color of other people's skin? My son at 4 years old learned the hard way that not all children go un noticed. On may 31st, my son was held down by three children and beaten. He was screaming for me, and I could not get to him fast enough. When I got to him he was hurting pretty bad. Later that night my son asked me what the N word was. How do you explain that to a 4 year old? Why should I even have to? These children that did this to him were 2 years older than my son, and they talk like that? You have to be kidding me. My son is Bi racial. He is mixed with both white and black. He is of a liter complexion than other mixed children. I guess he takes after me. I do not understand how a child that young could even have heard that kind of language from a 6 year old? I can only hope that he did not learn that from home. My son now has been trying to scratch his skin off because he wishes he was a different color. When I asked him why he did not like his skin color he told me that the kids made fun of him. He told me that he wishes he was daddy's color. His father is african american and of a darker complexion. I told my son that he was perfect just the way he is. I think some how deep inside that I know it was not going to be ok. I hurt every time my kids hurt. I eats me up inside to know that at the young age of 6, those children are already acting out in such a manner. What is going to happen when those children are 5 years older and completly out of control. Who's falt will that be? Society's for not stepping up and doing something about it while they are still young? The child's parents for rasing their children to be racist towards other people at such a young age? Who do you blame for the troubled youth that people dismiss all of the time? Who do you turn to, to make sure this never happens to my son again? The police were called and my son was taken to the hospital. He had deep internal bruising. The police say that there is nothing that can be done to these children because they are not 8 years old. I guess in Illinois the child must be 8 years old to be taken to Juvenille. The parents still have not been notified so who is to really blame here? The justice system? The parents, maybe? Why should my son suffer because children are running around with no supervision being hellions....It is not right and I am going to fight this until I can not longer do so. My son will see justice for what happend to him. I will make sure that these parents will be held accountable for their childrens actions. I am stunned to know that this happend with children so young. I know there is something that I can do to stop these crimes from happening. Hold on Son, I am here to help.....