Lots of people seem to be confused here
There are 5 colours so far:White, Pink and Brown (all SIM free) Black (T-Mobile exclusive) and Graphite (Orange Exclusive)
Black and Graphite are differant colours and are NOT availible SIM free through legitimate retail channels
Orange Hero Graphite edition
T-Mobile G2 Touch
These are both exclusive to thier respective carriers. For referance, here are the other colors that are availible off contract in the UK. If you buy from 3, you will get the white model, where as carphone warehouse stock the pink and brown models.
Standard White (with teflon coating)
Pink Model
Brown Model