What color is the heart again?
http://tuberose.com/Graphics/Bypass%20surgery1.gif
Blood is red usually but of different shades.
If you think I'm nitpicking you're right, which is my point. Although yes we are the same on a grander scale, we are also different in little ways. We have evolved to become sensetive to these tiny differences so that we can better identify each other(so you don't go hugging every old man you see on the street and calling him grandpappy). Racism is just an unfortunate biproduct of an essential evolutionary trait. Maybe if geneticists learn how to turn blacks white or whites black then we'll all be better off but I doubt it.