Pentachromacy
A Polychromatic color vision system that is 5-dimensional (generally, having 5 different types of Cones). Pigeons are a possible example of a Pentachromatic animal.
Human females that are Heterozygous for both their L and M opsins (i.e. simultaneously expressing genes for L, L*, M and M* Opsins) have the possibility of being Pentachromats, though – as with human Tetrachromacy – this is highly contested.
See also Tetrachromacy.