Final answer:
A stylist should choose hair color products based on the client's underlying pigment to achieve the desired hair color, which is true. Hair gets its color from melanin, and the type and amount of melanin influence the final color post-coloring.
Step-by-step explanation:
To achieve a client's desired hair color, a stylist should indeed choose hair color products based on the underlying pigment, which is a true statement. The pigment melanin, produced by melanocytes in the hair papilla, is responsible for giving hair its color. There are two types of melanin: eumelanin and pheomelanin, with eumelanin contributing to darker hair colors and pheomelanin to lighter, reddish hues. As people age, the production of melanin decreases, leading to the graying or whitening of hair.
When coloring hair, the type of melanin and its concentration influence the final color outcome. Hairdressers use this knowledge to select the appropriate color products, including the dye's color and developer, to ensure the client’s desired result is achieved. The chemicals in permanent hair dyes, such as oxidation dyes, work by removing the natural color and replacing it with a synthetic color, a process influenced by the hair's original melanin.