I've never heard choc-ice.
One of my Asians friends said he was called "Coconut" at uni by some other Asians and I've also heard Romesh Ranganathan say that word a few times.
It means brown on the outside, white on the inside.
I've heard "oreo" used a number of times to attack darker skinned people who might have a more conservative or less left leaning mindset.