Known as "Little x" and "Little y," (x,y) space can be defined as: (X)/(X+Y+Z) and (Y)/(X+Y+Z). X, Y, and Z are used as defined in CIE XYZ colorspace. (x, y) space is essentially a representation of chrominance alone. More importantly, (x,y) space is the plane in XYZ space in which the defined points for Red, Green, Blue and White lie.