Dye precursors in hair coloring products induce gradual color changes based on exposure and reaction with hair molecules.
Dye precursors are the components in hair coloring products that change color gradually by progressive buildup and exposure to air. These precursors react with the hair molecules to create pigments that develop over time, resulting in the change of hair color. An example of this process can be seen in the reaction of lead acetate in Grecian Formula with cysteine in hair to form PbS particles which change from colorless to yellow to black as they grow.
https://brainly.com/question/42212287