I spent some time last night leaning about what mutation my bird might be. I will post a better picture in a few minutes, but can anyone tell from the one in my avatar?
He is body is a pale blue, almost a violet or mauve colour (he reminds me of a light blue sky, with just a few wisps of cloud). His head is all white and the sides are grey, so I can't tell if his cheek patches are white or grey. He also has some really soft looking grey on the edges of his wing feathers.
I will try to take a better picture and edit this post later.
(Edited to add picture)