Did you know that certain molecules can actually have coloration? While we do not normally associate coloration with such a small particle of matter, certain molecular phenomena can indeed cause the reflection of selective wavelengths of light, creating color on a molecular level! These particles, known as chromophores, play an important role in the photopigmentation in the eyes.
Within molecules there are electromagnetic energy fields. These energy fields are caused by positive or negative charges of molecules due to their balance of protons and electrons. Oppositely charged particles attract and particles with the same charge repel one another. When atoms become cations or anions (positively or negatively charged, respectively), they exert these forces upon one another even within their molecules. When these forces become strong enough to affect them, the electrons in an atom may “delocalize” and become part of an extended energy field.
Chromophores are actually molecular regions or spaces created when two electron fields have an energy difference which falls into the visible light spectrum. As a light wave interacts with molecular fields, the energy differences and charges will correspond to with the wavelengths of light and elevate electrons from their ground state to an “excited” state, thus absorbing the energy of those wavelengths of light. The waves that do NOT resonate and are NOT absorbed and then reflected by the chromophore, creating the color we see.