I know it is many threads here about this topic and I've read most of them. But I have next questions, next step :) 1) (Summary) Does it true that composition and structure drive an energy levels of electron and it absorbs such wavelengths which correspond to jump to upper (not implicitly nearest) level and such wavelength is than missing in spectrum and results to different colour? 2) from 1) is for me understandable if and only if it is translucent and we are looking through (photon which come to my eye come through material) but how it works, when material is opaque? How is possible that photon is reflected from material back to my eye? Or why it reflecting only some wavelength (reason of colours)? 3) form 1) if some photon is absorbed and excite some electron. What happens than with this "system"? I suppose it relaxes in short time and release photon of same energy in random direction. And than? It excite another electron? Or what? 4) How is connected absorbing of photons (colours) and heating of material? I think that heating means stronger vibration of atoms or molecules (in lattice if it is such material). Is it true? But if photons only excite electrons how is it possible? Black coloured materials are heating more and absorbs more wavelength so I guess it is connected. True? Thank you for your answers.