Green, red, kidney, lima or soy are a few of the kinds of beans recognized on National Bean Day on January 6th. Celebrating the bean in all sizes, shapes and colors. Beans (legumes) are one of the longest cultivated plants dating back to the early seventh millennium BC. Beans are an important source of protein and very healthy choice for any meal or snack, and excellent source of fiber. Low in fat and high in complex carbohydrates, folate and iron. Black beans in a spicy TexMex meal.