Reference Source: Feeding Hummingbirds, Cornell Lab of Ornithology
Never use red food coloring in a hummingbird food, the red plastic on the feeder is more than enough color to attract the birds and the red dye might be harmful to the hummers. This applies to commercial food mix too, don’t buy it if it has red dye.
Don’t use honey in a hummingbird food, dilute honey is great food for bacteria and fungus.
The best mix for hummingbird food is table sugar and water. During dry weather mix 1/4 parts sugar to one part water. During wet weather you can increase the sugar content with a 1/3 to 1 mix because the birds don’t need as much water. (Plant nectar has sugar concentrations in this range)
If you make a large batch of food to keep on hand you must boil the water and then keep the mixture refrigerated to prevent bacterial and fungal growth. (You don’t want to make your hummingbirds sick)