Lumenis Splendor X Laser Hair Removal The Alexandrite wavelength at 755 nm, which is ideal for treating skin tones 1, 2 and 3 (fair and light skin tones). It is highly absorbed in melanin and is therefore not safe for use on darker skin tones. The Nd:YAG wavelength at 1064 nm, which is ideal for treating skin tones 4, 5 and 6 (4 being tanned skin and 5 and 6 darker skin tones) as the absorption by melanin is much lower than with the Alexandrite wavelength