The colored varieties are created by mixing cauliflower with other plants. For example, green cauliflower is a cross between cauliflower and broccoli. Beta carotene makes cauliflower orange. (It makes carrots orange too). Purple cauliflower is a type of broccoli that is purple. The additional colors add phytochemicals to the cauliflower. These are good for health. You can find some good recipes for cauliflower by clicking here.