What are the eating habits of a iguana?

Iguanas are supposed to be fed collard greens, mustard greens, And other greens. You can feed them a variety of fruits and vegetables too. Some people make Iguana salad which is a mixture of the greens, fruits and vegetables. I mostly feed my iguanas collard greens and mustard greens with fruit every day. I have read that if you feed your male iguana sweet potato during breeding season the orange coloring will come out more. I have three iguanas, one is about 3 years and the other two are about one year of age. All green iguanas.