Why are there no green stars?

Given that stars are known to span the visible spectrum—there are red, yellow, and blue stars, for example—green stars must also exist. Star color is correlated with temperature.

The color of stars in increasing order of temperature—red, orange, yellow, white, blue—is the key to the mystery of why the human eye is most sensitive to yellow-green light.

Because stars emit light at all wavelengths, even though they should appear green, the combination of all wavelengths causes the star to appear white to the human eye. In fact, our Sun is a yellow star, but it is so bright that the combination of all wavelengths causes it to appear white.

Green light is not prominent in the spectrum of most stars, so green stars are not commonly seen. Stars emit light across a wide range of wavelengths, but their colors depend on their surface temperature, which usually falls within the range of red to blue. That is why green stars are not observed.