Question

Which property of light waves specifies the color of light? Which is related to the energy of light?

Answer 1

Well, colour of light depends upon its wavelength `lambda` so that for example, we can see colours in the range from 400 nm (violet) to 700 nm (red).

For the energy you have to think of Einstein's relationship that gives you the energy `E` of a photon of light as:
`E=h*nu`
where `h` is Plank's Constant and `nu` is the frequency.