Purple cauliflower get their color from anthocyanin pigments, which are also found in red cabbage, red grapes, beets, red wine etc.
Unlike the more commonly found white variety, purple cauliflower is a heritage variety that comes from either Italy or South Africa, and contrary to popular belief, these are not genetically modified or artificially dyed - the purple color is naturally occurring.
Cauliflower is a member of the cruciferous family of vegetables, which also includes broccoli, kale, Brussels sprouts, & cabbage.
Purple cauliflower is rich in Vitamin A, B6 (pyridoxine), B9 (folate), C and K. It is low in sodium and calories and high in fiber. In addition, anthocyanins have numerous health benefits including quenching of free radicals (i.e. antioxidant benefits).