Kool-Aid used as a hair dye can damage hair depending on the person's hair and the dyeing method used. Using Kool-Aid as a temporary hair dye has mixed reviews, but most consider it safer than chemicals used in temporary dyes.
Kool-Aid used for hair dyeing should be the unsweetened variety to avoid sticky hair and potential eye irritation from the chemicals used in the sweetened variety. Kool-Aid reacts differently to natural hair colors and produces a much bolder color on naturally light hair, and longer hair requires using more Kool-Aid to fully dye hair. Using Kool-Aid to fully dye hair typically requires applying a paste and allowing the product to sit, while dyeing the tips of hair typically requires dipping the tips into Kool-Aid dissolved in boiling water.