Spectral lines of neon. An element's spectral lines are specific wavelengths of light that it emits due to electrons transitioning between different energy levels in the atoms, emitting light of a characteristic wavelength as they move to a lower energy level. As each element has its set of levels at unique energies, the emission spectrum of an element is like a fingerprint. Neon's emission lines are seen to be predominantly in the red region of the spectrum, and this light is commonly seen in neon lighting, and helium-neon lasers.