Looking at this store's Noh mask list, you will find that there are three Hannya masks that have different skin color: White, Red, Black. What is the difference between them. To tell the truth, it depends on their social position[rank].

Hannya(White): Hannya mask is sometimes called "Shiro-Hannya". The word "Siro" means "white" in Japanese. As you already know from the previous article, Hannya was a woman before. Shiro-Hannya was a very high classed woman. She was a noblewoman, so she did not have to go out, it never got burned on the sun, so the skin color is white.

Aka-Hannya(Red): The word "Aka" means "red" in Japanese. In contrast to "Shiro-Hannya", Aka-hannya was a lower classed woman who have to work outside. So her skin is red as it was burned under the sun.

Kuro-Hannya(Black): The word "Kuro" means "Black" in Japanese. Her skin color shows that she was living a life far from normal human life. She may lived in the mountain or wild environment. In Addition, if you watch each detail of three masks, you can find that a Kuro-Hannya mask has the wildest face.
These three colors of Hannya shows that whatever class she were, every woman have a possibility to be a mad(Hannya) with a jealous, envy and anger.

In this article, I talked about colors of Hannya mask. This rule also applies to other masks. Almost all the female mask are painted with white color. Because she was a noblewoman and lived inside in a palace. Some male Nohmask has a brown color. He was a fighter(Samurai) or a farmer who worked outside.