I saw a white deer this afternoon. It was nibbling at a security fence on the eastern side of the railway track between Bagshot and Ascot. The deer was a pure white, not just a yellowish white, and didn't appear to have any darker patches or spots. There were several other normal-coloured (grey-brown) deer with it.
I saw this animal again, a week or two ago, and it occurred to me that it might not be a deer but a large goat. I will keep a watch whenever I go that way (which is not very often nowadays).
I saw this animal again yesterday. It was sitting with some others, including a black one. They most probably are goats.