When you look up at the sky on a clear and starry night, you find millions of stars blinking at you in colors of blue, red, and yellow. Have you ever wondered why stars twinkle, and also why they have different colors? Twinkling of the stars are caused by the turbulence in the Earth's atmosphere, which is made up of several layers. Each layer is characterized by different temperature and density. Twinkling of the stars is caused by refraction of light, suring its passage through each layer.
The color of a star determines the temperature of its surface, which is turn is depends on the wavelenght of the light emitted by it. You need to know that a star emits light in various colors of wavelengths of the electromagnetic spectrum. If the temperature is around 3,000 K degrees, then the color of the star is red, and if it is 4,000 K degrees, then the color is orange. The color of a star is yellow, when the surface temperature is 6,000 K degrees. When it is above 8,000 K degrees, the color emitted appears white. If the temperature ranges between 20,000 K to 50,000 K degrees, then the star color is blue.
The wavelength of blue colored stars is short, and it is an indication that these stars have higher surface temperatures. The colors such as red, orange, and yellow have longer wavelengths of light indicating that the star's surface temperature is quite low. The ones such like Antares and Betelgeuse are orange in color, while Rigel is blue.