My favorite recipe for Humming bird food:

*Four cups boiling water
*One cup table sugar
(four parts water to one to one part sugar)
Don’t use artificial sweeteners as it will make them sick!
This will fill four 8oz. feeders
(save any leftovers in a canning jar or other lidded container in the refrigerator for up to a week).
Change the sugar water weekly. It’s starts to ferment during hot weather and smells bad and grows bacteria and mold.
Clean your feeders when you refill. A hot water rinse or a light soapy water wash in the sink will do.

Dissolve sugar in boiling water in a heat proof container and let cool completely before filling feeders. You don’t need the red food coloring at all. The hummers are smart and recognize the feeders without it. Besides, it’s not good for them anyway.
You can make this recipe a little more concentrated for cooler weather in the fall by only adding three cups water to one cup sugar. This gives them more energy to stay warm.
It doesn’t hurt to leave your feeders up as long as you can. It may help the stragglers make it on their long journey. I’ve had Humming birds as late as November here in Illinois.