The light at the back of the raindrop does not undergo total internal reflection, and some light does emerge from the back.

The Colors of the Rain by R.L. Toalson | Goodreads The Colors of the Rain by R.L. Toalson | Goodreads

But since the Sun's luminance is finite and its rays are not all parallel (it covers about half a degree of the sky) the luminance does not go to infinity.This gives us a spectrum of colours that range from the shorter blue and violet wavelengths through to the longer red wavelengths. The question of whether everyone sees seven colours in a rainbow is related to the idea of linguistic relativity. He coined the idea that there are seven colours in a spectrum: red, orange, yellow, green, blue, indigo and violet (ROYGBIV).

The Color of Rain - Hallmark Drama The Color of Rain - Hallmark Drama

However, remember that there is also a whole range of colours, so many that we cannot distinguish them all with the naked eye. Later he included orange and indigo, giving seven main colours by analogy to the number of notes in a musical scale. The radius of the disc depends on the wavelength of light, with red light being scattered over a larger angle than blue light. Someone who appears below or near the "end" of a rainbow to one viewer will see another rainbow, extending from his or her own horizon.The number of colour bands of a rainbow may therefore be different from the number of bands in a spectrum, especially if the droplets are particularly large or small. Perhaps the most famous piece of mythology surrounding rainbows is the Irish legend of the pot of gold at the end of a rainbow. During this time, sunlight travels further in the atmosphere, and shorter wavelengths (blue and violet) have been scattered.