Why do materials absorb and reflect different wavelengths of light?

[hokhani]

I don't know the reason of materials' color? Why one matter is blue and another is red? Which mechanism is responsible for their color; Absorption, Luminescence, Scattering, Reflection?

 

[CompuChip]

Short answer: It depends :)

Longer answer: In most cases, I would say that absorption / reflection is the reason that we see a certain color: if you shine white light (i.e. a mixture of all frequencies) onto a material, it will absorb some of the colors and reflect the rest. However, there are special cases in which the color is caused by another mechanism. For example, LEDs work by virtue of luminescence and the sky is blue because of scattering and not because it absorbs all other colors.

 

[hokhani]

Short answer: It depends :)

Longer answer: In most cases, I would say that absorption / reflection is the reason that we see a certain color: if you shine white light (i.e. a mixture of all frequencies) onto a material, it will absorb some of the colors and reflect the rest. However, there are special cases in which the color is caused by another mechanism. For example, LEDs work by virtue of luminescence and the sky is blue because of scattering and not because it absorbs all other colors.

Thanks a lot.