In one, all; in all, one.

From a Buddhist Sutra (and a tee-shirt from Nara temple in Japan)

In white, all colors. In all colors, white.

All it takes is some heated sand and water (that is, a glass prism) to show that!

You have no receptor in your eye for yellow.

Rainbows aren’t things. They are contingent processes of light, water, quantum electrodynamics and an eye and brain

Having no mass and traveling through a vacuum at light speed a photons’ universe is one of time dilation such that the next tick of the clock never happens, so no time, and space contraction so there is here, so no space. So, see that star thousands of light years away here and now?

The Pleiades in the night sky

Photons pop in and out of electrons. That’s what a “quantum jump” is: an electron absorbs a photon (only some energies are allowed for a given orbit in a given atom. That’s quantum electrodynamics) and gets the right amount of energy to be in (jump to) a different (higher energy) orbit around the nucleus of the atom (or spits out a photon and goes to a lower energy orbit).  So atoms are constantly creating and absorbing light. 

Not atomic orbitals, but a cool picture that reminds me of atomic orbitals

You can pile up photons in the same place, but not electrons and protons and neutrons. That’s why you experience things as solid, but not light. Light has energy though, and so it can cut through things and burn you up and give you cancer. However, it helps if you want to read a book at night.