An estimated nine to twelve percent of the male population suffers from some form of color vision deficiency, commonly called 'color blindness.' It is important for computer interface designers to take into account and eliminate, if possible, any potential confusions that can arise because of color vision deficiencies. There are two major types of color blindness. The most prevalent causes are confusion between red and green. This type affects approximately eight to ten percent of the male population. In another type, an additional one to two Percent of men suffer from a deficiency in perceiving blue/yellow differences. Less than one percent of women suffer from any form of color blindness. To understand color blindness better, it is helpful to be familiar with the ways in which colors differ from each other. One standard way to discuss color is to divide it into hue, saturation and brightness (HSB).