I am not able to understand why compounds have colour. I have read that it is due to excitation of electrons from one atomic/Molecular orbital to another because of which certain wavelengths are absorbed, And we can see the "complementary colour" of those wavelengths. What I don't understand is that when an electron gets excited, it has to eventually de-excite and come back to its initial orbital. Now let's say that on average an electron remains excited for some time ##t##. After ##t## time, shouldn't there be an equal number of electrons getting excited per sec to those getting de-excited? If this were to happen, the same wavelength that is absorbed by one atom should be emitted by another atom? Wouldn't this mean that the compound is colourless? I am confused, and any clarification would be greatly appreciated.