How are the different colors observed related to the electron structure of the atoms?

Every atom has one or more electrons surrounded its nucleus. The electron emits light after changing from a high energy state o to a lower energy state which is known as transition. The wavelength of this light is unique to each element because each atom of a particular element has a different transition energy. And since we humans perceive different wavelengths as different colors, all the colors are related to the electron structure of the atoms.