Bob, We have a yard full of wild black raspberries. We have planted two kinds of red raspberries, and just planted gold raspberries. We have had abundant crops of blacks and reds mere feet from each other. No problem with cross pollination. I think I read somewhere that there may be disease issues, but we have had no trouble yet. Enjoy those berries. Ted

I don't quite understand the disease issue thing. Seems to me if you get disease you're going to have disease whether you have red or black in that spot and then it's going to spread to other patches whether they're the same color or not.
But yes, allegedly disease is the only issue with having both.

I have a wild bunch about 15' from my reds.

Thanks for the replys