Different sources of light have a different colour and this is regularly known as colour temperature. The two ends of the scale are red and blue.
The temperature that candles and sunsets emit is close to red, which is why they have a warm look. On the other hand, a clear blue sky will give off a cool blue light which is towards the cool end of the scale.
This scale is measured in Kelvins (K) and in most cameras, you can manually change this setting to suit the light levels in which you’re shooting, adjusting them to fit the image.
Another option for those less inclined to continuously change the kelvin as you shoot in different light sources is the AWB (auto white balance) system. This uses electronic filtration in the processing stage to correct the colour temperature to what it measured in the scene.