In a British study using different colored bird feeders, birds were most attracted to silver, blue and green. However, such preferences varied according to species, with goldfinches preferring green.
Preferences also varied broadly with the season. While silver was the most popular color among birds in the winter, they showed more of a preference for blue in the summer.
With four color receptive cones, birds are much more sensitive to color than humans, who have three. In addition to being able to notice subtle color differences, birds are able to see light in the ultraviolet range. They are like bees in this respect, which also have four color receptive cones.