These new color matching functions correspond to imaginary primary lights X, Y, and Z (CIE XYZ color space). All colors can be matched by finding the amounts , , and analogously to , , and as defined in . The functions , , and based on the specifications that they should be nonnegative for all wavelengths, be equal to photometric luminance, and that for an equienergy (i.e., a uniform spectral power distribution) test stimulus.
These new color matching functions correspond to imaginary primary lights X Y and Z (CIE XYZ color space) All colors can be matched by finding the amounts   and analogously to   and as defined in  The functions   and based on the specifications that they should be nonnegative for all wavelengths be equal to photometric luminance and that for an equienergy (ie a uniform spectral power distribution) test stimulus