My DH is white, I'm black and we have twin boys. One is fair with blue eyes and fair hair like DH, the other is brown with brown eyes and dark hair like me. Funnily, the hair of the fair twin is afro in texture whereas the brown twin's hair is more caucasian in texture. One would have thought it would have been the other way around.
I am often asked if they are twins but more especially if the fair one is mine!!
The rudest comment I had was in the supermarket once when a racist prat said that I was ugly but the fair twin was beautiful and completely ignored the dark one.
DH does worry that the dark one will be bullied more than the fair one because of his colouring and that the fair one will be teased for having a black mother even though he looks white.