How are temperature and color related?
The amount of light produced at each wavelength depends on the temperature of the object producing the light. Stars hotter than the Sun (over 6,000 degrees C) put out most of their light in the blue and ultraviolet regions of the spectrum. Stars cooler than the Sun (below 5,000 degrees C) put out most of their light in the red and infrared regions of the spectrum. Solid objects heated to 1,000 degrees C appear red but are putting out far more (invisible) infrared light than red light.