The energy of a photon is directly related to its frequency or equivalently, its wavelength, according to the equation E = hf, where E is the energy of the photon, h is Planck's constant, and f is the frequency of the photon.
Indigo light has a higher frequency and shorter wavelength compared to green light. Since energy is directly proportional to frequency, photons of indigo light have higher energy than photons of green light.
Therefore, indigo photons are more energetic than green photons.