FISH CAN SEE IN COLOUR
DO fish see different colours the same as we do? Coarse fish have the same light-reactive cells in their eyes as humans, so they can see colours, although they might perceive them slightly differently us. More importantly, though, coloured baits really do stand out against the generally brown lake bottom or riverbed.
In very deep water, say more than 20ft, colours at the red end of the spectrum are lost as these wavelengths of light are absorbed by the water. Shallower than this, though, colours stand out well.