Which color is the strong laser light from the laser pen, green, red, blue or yellow? It is not only to look at the power of the laser pointer and the reflectivity of the surface but also the sensitivity of the human eye to color. Because the eye is most sensitive to green laser with wavelength of 495-570nm. The sensitivity to red or blue laser wavelengths is reduced, so the green laser appears brighter at the same power. The most common is green laser light with a wavelength of 532nm, which can be clearly seen at night even at low power laser. 5mW laser is the safest to use and can be seen in darker environments. It is best to wear safety laser glasses, but also to avoid laser direct to the skin.