Acquiring and setting up Gyazo for use couldn't be easier, in fact, it literally can be done in two easy steps. 1  Download the .exe from here. 2  Run the .exe, make sure that you tick Create a Quick Launch icon box, the desktop shortcut option is up to you.
Different birds like different colors. Hummingbirds are attracted to a broad range of colors including red, pink, orange, and yellow; Orioles enjoy orange, Goldfinches and warblers prefer yellow, and bluebirds and jays are drawn by blue.
All blue coloration in birds and butterflies, for example, is structural in nature. Blue eyes in humans are caused by the same Rayleigh scattering phenomenon @tennesseejac mentioned. So it would seem that only one remote corner of the animal kingdom has evolved an actual blue pigment.