Red - help memory function, urinary tract health, and makes your heart healthy. They also often very high in vitamin C, which helps encourage cellular renewal in your body.
Orange - give us the right amount of potassium and vitamin A, which keeps our eyes and skin healthy, and protects against infections. They are also known to boost the immune system because of the vitamin C content in many of them.
Yellow - are high in antioxidants like vitamin C. Vitamin C keeps our teeth and gums healthy, helps to heal cuts, improves the mucus membranes (like when we have colds), helps to absorb iron, prevents inflammation, improves circulation, and therefore prevents heart disease.
Greenish/White - create an anti-bacterial, anti-fungal, and anti-viral chemical environment in your body. Some white foods prevent cancer and heart disease, and lower cholesterol levels.
Blue /Indigo - anti-aging properties, tons of antioxidants, improve circulation, prevent blood clots, help prevent heart disease, help memory function and urinary tract health and to reduce free radical damage
(info from vegan-nutritionista.com)