You can have a lot of fun with beardie color vision, actually -- mine has favorite colors that he reacts to strongly if he sees them. Red, orange, and green are the big ones. Yellow is less exciting to him but he still tends to notice it. He generally ignores blues and violets/purples, but sometimes I've seen him pay odd amounts of attention to something blue, too. It probably has to do with the colors of the food he tends to get. XD He doesn't get much blue or purple food but lots of stuff that's red, orange, yellow, or green.