For me it is just silly to write off a potential relationship based on a person's race or culture.
I have no particular culture, unless you count drinking heavily and partying until you can't stand as cultural rituals. I doubt any of us here ascribe to much from our cultural heritage, except for the fun parts, like drinking sorghum beer and watching the reed dance (planning a trip to Swaziland for this shit by the way).
There are plenty of white girls who grew up in a mixed demographic. They really don't see race, as much as we would like to deny it and say they are just pretending etc.
I have white friends who are more black than me, hanging out in the hoods and walking around in parts that I wouldn't go without a weapon. I felt really embarra**ed once, when a white boy had to introduce me to dudes from my old neighbourhood.
So, I really see no reason why you should not at least try to make a relationship with a person from another relationship work. If it doesn't work, then so be it. I'm sure many of us have had relationships with girls from our own race also fail because of silly reasons. Only difference is then we don't have something as convenient as race to blame.
The race card pisses me off so much lately.
I generally don't date coloured girls, unless they are girls from a predominantly black or white area, cos then at least they don't have that narrowminded approach that pisses me off so much (like coloured girls asking me why I dat black girls and making disgusting comments about their hair, while my girl has naturally long straight hair and they all have weaves etc.). That's not to say I won't give them a try though.
This sounds corny and cliched as hell, but we really need to look past race and try to get to know each other, instead of focusing on bullshit social constructs and stereotypes.