Light properties, such as reflection and absorption, is SOLELY based on COLOR. This principle also applies to virtually all light technology & devices such as laser, LLLT, IPL, LED, diode & etc.
Based on this principle, it is essential to apply the most effective laser energy settings, especially during very first few treatment sessions while hair is the most coarse, thick & dense to obtain the most reduction result. The later sessions, the less the reduction results because paler colour can absorb less light, thus less effective. Thus, initial patch test is super important to ensure your therapist can use high settings but not overtreat you.
For more info => All the Client Need to Know about Laser Hair Removal