Traditional lasers work best on dark, coarse hair because they target the melanin (pigment) in the hair follicle. Darker hair absorbs more laser energy, making treatment more effective. Lighter brown hair might respond but could require more sessions, and very light blonde or gray hair typically doesn't respond well to conventional laser treatments. However, newer laser technologies are getting better at treating a wider range of hair colors. The best approach is to have a consultation where they can assess your specific hair type and recommend the most suitable laser system.