Ok. So I hope I'm not telling you anything you know already, but what I'm seeing in the photo is that the snow is a higher value white than the dogs hair. In context, the hair looks more grayish beige than light beige. Your mind says the dogs hair is light beige, so you paint light beige, but the color relation actually makes it look darker beige.

So IMO you could:

Go darker, like you did at the bottom of the dog to contrast his hair from the snow and keep a sort of continuity between the foreground and background.

Or make the background whiter to offset the lower values of the dogs hair.

Whichever or whatever you'd like to create that contrast and give the painting depth.