Carbon steel tends to go grey over time, even if looked after and oiled properly etc.
Does anyone use any form of polish on their razors from time to time to prevent this from happening, like you might polish jewellery occasionally?
Easiest hassle free way to maintain the shiny look of your CS straights is to move to the desert. The dry air will suck all the moisture away from the cold steel and keep the razors in pristine condition.