Red foods, such as tomatoes and watermelon, contain lycopene, a phytochemical that may help protect against prostate and breast cancers.
Alpha and beta carotene make foods like carrots and sweet potatoes so brilliantly orange. The body converts these compounds into the active form of vitamin A, which helps keep your eyes, bones and immune system healthy. These phytochemicals also operate as antioxidants, sweeping up disease-promoting free radicals.
Yellow & Green, part 1 (leafy greens)
Many yellow and green vegetables are good sources of lutein and zeaxanthin, phytochemicals that accumulate in the eyes and help prevent age-related macular degeneration, a leading cause of blindness in older people. Leafy greens are also rich in beta carotene.
Green, part 2 (cruciferous)
Cruciferous vegetables, such as broccoli and kale, provide compounds called indoles and isothiocyanates, which may help prevent cancer by amping up the production of enzymes that clear toxins from the body.
Blue and Purple / Deep Red
Blue, purple and deep-red fruits and vegetables are full of anthocyanins and proanthocyanins, antioxidants associated with keeping the heart healthy and the brain functioning optimally.
(information was found from eatingwell.com)