The same logic stands good for lights. Try using LEDs to guide someone or as a marker. Green can be seen from the farthest distance.
All this while we thought red having the largest wavelength would be visual from
longest distance. However, it is not so as Red has a danger of causing damage to the eye also.
The green color was created by analyzing the way the rods and cones in our eyes are stimulated by different wavelengths of light. It was found that the human eye is most sensitive to light at a wavelength of 555 nanometers—a bright green.