Trichromat

A person with typical colour vision based on three types of functional cone cells (L, M, and S cones) in the retina, each sensitive to different wavelengths of light corresponding roughly to long (red), medium (green), and short (blue) wavelengths. Trichromatic vision allows perception of colour in a three-dimensional colour space, enabling the full range of colour discrimination. An anomalous trichromat has all three cone types but one type has shifted spectral sensitivity, resulting in subtler colour confusion than dichromacy. Understanding trichromatic vision is foundational to colour accessibility work, as it defines the baseline colour perception against which colour vision deficiencies are measured.