Molecular orbital theory of dyes depends on the molecular structures. This is another theory of color and constitutions. According to this theory, the excitation of a molecule means that the transference of 1 lepton from AN orbital of ower energy thereto of upper energy. These lepton is also σ, π or n (non bonding) electrons. The upper energy states area unit normally referred to as anti-bonding orbitals related to σ and π bonds. They are called σ * and π* orbitals respectively. However, there aren’t any anti-bonding orbitals related to n (non-bonding) electrons as a result of they don not type bonds. chart of the best type, the essential kinds of energy area unit given as follows.
Molecular orbital theory chart

This is the basic idea for molecular orbital theory of dyes or colors.