I had no luck with hummingbirds at the beginning of the summer using the powdered mix you get at lowes.
Started making my own at a 1:4 sugar to water ratio.
At first that didn't help much, was using filtered water from the refrigerator, boiling it, mixing, and food coloring. Not many birds.
Then I hit on it. For the past month I have been using bottled water, and the usual boil and 1:4 sugar. No food coloring.
I have hummingbird fighter jet shows all day long. 2 window feeders and 1 hanging from the deck on a shepherds hook. They are nuts! They'll come right up to feed even when I'm on the deck.
I think the bottled water was the difference. The birds here just have expensive taste.
I let my dad know, and he tried the same thing at his house and right away he had hummingbirds all over too. Give the bottled water a try if your hummingirds are being picky!