There are two basic reasons for different star colours:
- Temperature – cooler stars are red, warmer ones are orange through yellow and white. The hottest stars shine with blue light
- Age – As a star ages it produces different chemicals which burn at different temperatures. We can use a star’s colour to show its relative age
The mix of other elements contributes to the color spectrum of the stars they create. Stars exist in a range of colors: red, orange, yellow, green, white and blue with red being the coolest and blue being the hottest. Blue stars are hottest because their nuclear fusion remains fast & the photon of light produced from fusion have more energy.