Question: why are there coulers???

Emma Trantham answered on 5 Jul 2012:

The light that comes from the sun is made up of lots of different wavelengths and it is these different wavelengths that are different colours. (You can see all the different colours of visible light that come from the sun when there is a rainbow: red orange yellow green blue indigo violet)

When light hits something the object absorbs some wavelengths and reflects others, eg. an object might absorb all of the red-yellow light but reflect the blue light and so the object looks blue to us.

Does this answer your question?