The three determining elements of a dichromatic opponent-colour space are the missing colour, the null-luminance plane, and the null-chrominance plane. The description of the phenomena itself does not indicate the colour that is impaired to the dichromat, however, it does provide enough information to identify the fundamental colour space, the colours that are seen by the dichromat. This is based on testing both the null-chrominance plane and null-luminance plane which intersect on the missing colour. The cones excited to a corresponding colour in the colour space are visible to the dichromat and those that are not excited are the missing colours.
Dichromacy
Consanguinity
Heredity
Chromosomal fragile site
Genetic predisposition
Nuclear sexing
Sex linkage
Premorbidity