Cotton candy can be made in many machines with 100 percent cane or beet sugar including regular granulated sugar. In order to make colorful cotton candy like the kind you find at fairs or the circus, you will need to tint the sugar before you add it to the cotton candy machine. This can be done with liquid food coloring which can be purchased at any grocery store. Pour 1/2 cup of sugar into a jar. Tint the sugar in small increments such as 1/2 cup as attempting to color large mounts of sugar can be difficult and cause a blotchy or uneven color. Add two or three drops of liquid food coloring to the sugar. Start with a small amount because you can always add more food coloring later to darken the color. Seal the jar tightly with the lid and shake the jar until the sugar is one uniform color. Continue to tint sugar until you have enough to make cotton candy.