Stages of a Jedi
(based on my AU Narglatch in Shaak's Clothing)
Jedi Padawan Sheev Palpatine found himself in serious trouble when he forged a red lightsaber in secret, but was allowed to keep it after showing that precedence could be found in the Order.
Once Sheev Palpatine became a Jedi Knight, he entered the Consular rank and consequently began to take on some of the mannerisms and dress of the politicians who surrounded him.
Over time, few noticed the darker trend of Consular Palpatine's Jedi clothing, or the higher quality of his robes.