Birds are not color blind. These animals actually have more advanced color vision than human beings. Birds have photo pigments with sensitivities at four or five peak wavelengths, making them either tetrachromats or pentachromats.
Humans are trichromats, meaning they have photo pigments with detection at three peak wavelengths. Some eyes of birds have a much greater proportion of cones to rods than humans. The structure of a bird retina is also more complex than a human's retina. For example, eagles have larger retinas than humans. Birds rely on their comprehensive visual perception to identify prey and carrion left behind by other predators.