I am partially colour blind, so I can only see only the three primary colours of a rainbow, as can 99.9% of all colour blind people. Very few fail a lantern test.

On the other hand, I can spot a Birch Partridge (Ruffed Grouse) against a "camo" background and point it's location out to others who cannot see it, even when it is in "full view". I have spotted them when all I could see was part of their head at twenty yards.