Some even come in four.

White-throated sparrows have two different types of coloring, white-striped and tan-striped.  There are white-striped females and white-striped males as well as tan-striped females and tan-striped males.  White-striped birds of both sexes tend to be more territorial and aggressive than the tan-striped birds of either sex.  White-striped sparrows form the most successful mating teams with tan-striped birds.

To learn more about the making of this painting, visit this article on my blog.