More than 35% of the U.S. is comprised of non-Caucasians.  This includes Hispanics, African-Americans, Asians, and Native Americans.  There are several different methods of classifying these different skin types, but the most common is the Fitzpatrick Photo type.  The Fitzpatrick method takes into account not only the color of unexposed skin, but also sensitivity to light and sunburn and tanning history.  More elaborate Fitzpatrick scales also take into account presence of freckles, hair and eye color.  The following chart is a good guide regardless of race for the purpose of laser hair removal.

The reason that certain races have darker skin colors is due to the fact that melanosomes are larger and show a higher degree of melanization.   There is also a greater production of melanosomes in melanocytes and a higher degree of dispersion in the keratinocytes.  There is also a slower rate of degradation.  These factors are usually dependent on heredity and racial factors.  The combination of these factors can be the reason we see varied skin tones among the same race.  In terms of laser hair removal, darker skin types will need longer wavelengths for better safety.  Longer wavelength lasers such as the Nd: YAG mean less scatter in skin and deeper penetrations.  The hair bulb can be as low as 7mm in depth.  These lasers target deeper hair very effectively, but are not as effective for the finer, closer to the surface hair.  Melanin is found in the hair bulb, shaft, outer root sheath, and also the dermal-epidermal junction. Today's lasers user the Fitzpatrick scale to describe their variances.  For example, ruby lasers are considered limited in use because they only are able to safely treat Fitzpatrick skin types I and II.  Alexandrite and diode lasers are considered more useful because they can treat type’s I-V.  Nd: YAG lasers.an treat all skin types, but are not as effective with finer hairs.