Some do, some don't, and the spectra that animals can see varies from 2 channel, as in dogs, to three channel (humans) to sixteen channels in the completely nutso mantis shrimp. You wondered about predators, however. read more
Color blindness is a misleading term. It does NOT mean that the individual can't see color. Cone cells in our retinas come in a few different"flavors" that allow different wavelengths of color to be absorbed. In normal human vision, we are trichromatic - that is, we have three different types of cones. read more
Generally, omnivores eat fruits and vegetables freely, but they can’t eat grasses and some grains due to digestive limitations. Omnivores will also hunt both carnivores and herbivores for meat, including small mammals, reptiles, and insects. Large omnivores include bears and humans. Examples of medium-sized omnivores include raccoons and pigs. read more