Baker Creek Heirloom Seeds has a whole bunch of open-pollinated/heirloom vegetables/fruits of unusual colors (their website front page at the moment just so happens to be showcasing many examples of their purple produce!)

I try to mostly grow open-pollinated/non-hybrid/non-GMO plants because it means that I have the option to save seeds and know the offspring will be the same variety with the same traits. I also don’t have to worry if I want to sell produce at my local farmer’s market that I’m going to get sued by some asshole at Big Ag for selling a “patented” plant (which as preposterous as it sounds can actually happen).