Ash grey
The grey of what fire leaves — colour that is evidence of a finished burning.
Ash grey in a dream is the dream's image of the colour fire leaves behind, the grey of cooled remains. Ash is not nothing; ash is the form a thing takes after it has finished burning. The dream brings ash grey when something in your life — an anger, a passion, a piece of work — has burned all the way through, and what is in front of you now is the residue. An ash grey gathered into a container is the dream telling you the residue is being kept on purpose. An ash grey blown about by the wind is the dream noting that the burning is over and you are still standing in the place it happened, with the air full of what is left.