Yes, birds see color, better than we do. According to the Handbook of Bird Biology (Princeton University Press), birds see a wider spectrum of colors than humans do. Birds see the colors we see plus a portion of the UV light range. Colors are important to birds. Females of many species choose mates based in part on the intensity of a male's plumage colors. There is a cost to being among the chosen, however. Males give up energy to create bright colors. The energy price weakens their immune systems, and makes them more susceptible to disease. The drive to continue one's genetic heritage, however, is over-riding. The reader who asked this question was going to use red paint to mark a feeder filled with peanuts in hopes that the jays would learn to associate the color-marked feeder with a favorite food. My guess is that the jays would quickly learn to find the peanuts, color coding or not. Birds have spectacular memories when it comes to food locations. They don't need color clues.