Unlike good little electrons, proton and neutrons, photons do not obey the Pauli Exclusion Principle. Any number of photos can pile up on top of each other while traveling in the same direction at the same time. This is fortunate. Since one photon would probably always be coming from every direction, everything would look dim grey. Differences in brightness depend on photons being able to bunch together.
Their disobedience can result in a bit of collateral color distortion which gives them away. For example, take those distant mountains’ purple majesty. Despite appearances, up close they do not appear purple at all. What happens is this:
While traveling from afar, those mountain photons get joined by other photons from the sun that have been scattered by water molecules in the air along the way. Because more short wavelengths get scattered, more short wavelength photons than long ones join those coming from the mountain. Given enough distance these hitch hikers predominate.