Oh I absolutely ADORE hummingbirds! They are my most favorite kind of bird (I'm also very partial to penguins...so funny to watch, heehee...)
Anyway, I make my own hummingbird nectar from sugar and water (1 cup of sugar and 4 cups water) as I believe it's better for them than buying the stuff with food coloring in it. It is also a lot cheaper to make your own. All you need is the feeder to have red parts on it to help attract the birds. The nectar can be clear and they LOVE it!
