the color and temperature of stars are closely related. which color star is the hottest? black red yellow blue

Brief Explanations:

Stars emit light based on their temperature. According to Wien's displacement law ((\lambda_{max}T = b), where (\lambda_{max}) is the peak wavelength of emitted light, (T) is the temperature, and (b) is Wien's displacement constant), higher - temperature stars emit light at shorter wavelengths. Blue light has a shorter wavelength compared to red and yellow light. Black is not a color of light emitted by stars in the context of thermal radiation (stars are not black - body radiators in the sense of emitting "black" light; they emit visible light at various wavelengths depending on temperature).

Answer:

blue