The perceived power of laser light isn't solely determined by its colour but by the energy output and wavelength of the laser. However, in terms of visibility and how our eyes perceive brightness, green lasers often appear the most powerful to the human eye. This is because the human eye is more sensitive to green light, around the 532nm wavelength.
Although blue or red lasers can have equal or greater actual power levels, green lasers are more efficiently detected by our eyes, making them appear brighter and seemingly more powerful under identical conditions.