The most common form of colour blindness is red-green colour vision deficiency, which is a type of anomalous tricromacy. This means that 1 of the 3 cone types – in cases of protananomaly the cones associated with red colour vision, or in cases of deuteranomaly the cones associated with green colour vision – are sending the brain incorrect signals during colour perception. This error makes distinguishing hues challenging, especially if they have a lot of red and green components, and can lead to confusion when identifying colours like red, orange, brown, purple, and green in various daily situations.
This case is separate from the rare conditions of partial colour blindness (dicromacy) where only 2 cone types are functional, and complete colour blindness (monocromacy) where only 1 cone type is functional.
