basically light travels into the eye to the retina located on the back of the eye. the retina is covered withe millions of light sensitive cells called Rods and cones. when these cells detect light they send signals to the brain that help detect color.
the color of an object is determined by the wavelengths of light that it reflects. it's determined by the arrangement of electrons in the atoms of that substance that will absorb and re-emit photons of particular energies according to quantum laws.
