Sexist hummingbirds?

I love hummingbirds. I was overjoyed to discover they liked us too, and faithfully return to our yard every spring. They drink quite a bit during the summer, so I am often in the kitchen, making up a new batch of sugar water for them. Nearly every time I look out the kitchen window, I see a hummingbird. Sometimes two, or three, or even four hummingbirds will be zipping around the feeder.

I let the boys take turns telling me what color the sugar water should be. TJ went first this year, and selected blue. I made a big batch of it up (I refrigerate the extra, and warm it to room temperature before serving it to the birds. Works great!), so we've had blue food for awhile. Here's a hummingbird about to dine on TJ's blue food (look closely...it's to the left of the feeder):


I asked Sam what color he wanted me to make next and he immediately responded with "Purple!"

TJ was horrified. He said, "Sam! If you do purple food, only the girl hummingbirds will come to our feeder!"

Really? Are hummingbirds sexist? Can they even see color???

I laughed and told Sam that purple food was just fine and informed TJ that we couldn't tell the boys from the girls anyway, so what did it matter?