Over a millennia ago the world was rent with colour. As it was over 1000 years ago, there is little knowledge, but all of the histories maintain that the sun turned into a spinning orb of colour, every colour visible, before a brilliant white flash and then all was colour.

The Spectral Church provides the most doctrine around what happened here. According to the church, this was the outcome of a battle between Colouria and The Dark One. The Dark One's influence had grown strong in the land and he had attempted to drain Colouria of their light.
The ensuing struggle between the two deities led to a clash of power that had never been seen. Leading to the spill.