my DH is half african (west) and half bajan (so essentially mixed race himself at face value if you ignore slavery from West Africa to the caribbean), but was born in England. He classes his ethnicity on forms as afro caribbean and doesn't mind being called black.
I'm white and born in England. Our DD is mixed race. On forms we put her down as black-mixed or white - mixed caribbean.
I must admit I really dislike it when people call DD half caste. We don't live in a caste system, so how can be half of something that is non existant?
When DD noticed that she doesn't look quite like DH or I and she was asking about colour I explained that DH is called Black and I'm called White and she is mixed (half mummy and half daddy), but in real life DH is Dark Brown, I'm Pinkish and freckly and DD is light brown.
I won't mind if DD denotes herself as white, black, mixed or other when she's older. Afterall, aren't we all just individual anyway?
Oh and with regards being called black or not being able to sing baa baa black sheep. We went to see DH family at the weekend. His brother has a 'white' partner also (in fact all his sibling are in mixed white/black relationships) and in their living room they had a golly wog and when DD asked me what it was I said a golly wog and the world did not stop, there was no sharp intake of breath, because when I was a child it was called a golly wog. It turned out that it was his brothers when he was a boy and it was a Robinsons golly wog that you saved for from the side of the jam.
DH does think that some black people have a bit of a chip on their shoulder about what to be called because he said, you generally know if what is said is meant offensively.