According to international research carried out by the Field Museum in Chicago, all bird feathers are made of keratin, the same protein that is present in human skin, nails or hair.
In addition, they have cells that contain pigment-producing organelles (i.e. melanosomes). People also have melanosomes, since they are responsible for producing melanin and coloring our hair and skin.
However, pigment is not the only way that birds can obtain color. The shape and distribution of melanosomes can influence the way light bounces off them, resulting in bright and vivid colors. Thus, according to the researchers, the feathers of birds are organized in layers and, when light bounces off these layers, bright colors appear as if it were a soap bubble.
On the other hand, the researchers also found that the thickness of their feathers and the shape of the melanosome affects the color of their plumage. In fact, these traits allow them mix and match more colors than other species of birds.
Now, scientists are trying to find out how the structure of feathers affects color and what are the genes they are behind the bright colors in the plumage of the birds.