is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions
Color blindness or color vision deficiency is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions. Color blindness affects many people in a population.
Color blindness could impare the User Experience if color is used in such a way that it is the only key for a user to know what action to take, the state an element is in or grouping of elements. Having more visual cues is essential for color blind users.
Questions having the color-blindness tag regards the User Experience of colors in design to inform a user of a certain state, action or group of elements.
More to read: http://en.wikipedia.org/wiki/Color_blindness
