I have never for once encountered an half-caste (whose parents are combination white+black race) having a dark complexion.
Why is this so?

Half - caste?

Half caste is kind of
Mixed race, bi-racial or whatever.

I heard all versions as a kind, Mulatto, unfortunate European, made in Taiwan and so many more. Please don`t use that again . It is offensive to them.
.. and yes they do have dark ones, my sister is really dark but she has lovely straight hair. Something of both sides is always there.

mutter:
Half caste is kind of
Mixed race, bi-racial or whatever.

I heard all versions as a kind, Mulatto, unfortunate European, made in Taiwan and so many more. Please don`t use that again . It is offensive to them.
.. and yes they do have dark ones, my sister is really dark but she has lovely straight hair. Something of both sides is always there.

I know the right word is mixed race but i only wanted to use one familiar to we nigerians. I hope you didn't school in France . You sister is dark? Where do you parents come from?

Actually grew up and schooled in Nigeria before I left. Yes I am a bit fairer but have curly hair. My parents come from Nigeria/Europe.

offspec:
I know the right word is mixed race but i only wanted to use one familiar to we nigerians. I hope you didn't school in France . You sister is dark? Where do you parents come from?

mutter:
Actually grew up and schooled in Nigeria before I left. Yes I am a bit fairer but have curly hair. My parents come from Nigeria/Europe.

Interesting.... But i believe when you say your sis is dark, maybe you mean not as white as other of her siblings