The three petals that grow upward on the top of the iris are called Standards. The three that hang down are referred to as Falls. The smaller often fuzzy or hair like parts in between are the Beard. If an iris is all one color it is called a Self. When I first started growing irises I was enamored of the deep purple to velvet black Selfs.
Bearded irises are among the few flowers to come in a true black.
In fact, they come in every color except green. One of the first Irises I won a ribbon with in local competition was an old fashioned purple Bi-tone called Lothario Again. Bi-tones as their name suggests are two shades of one color, in this case, violet silk Standards and deep purple velvet Falls. When the Standards and Falls are different colors they are referred to as Blends. The real mystery group is the Plicatas.