The Spirit of Christmas Present in Dickens' Christmas Carol - who is of course Father Christmas - wears Green:

It was clothed in one simple green robe, or mantle, bordered with white fur. This garment hung so loosely on the figure, that its capacious breast was bare, as if disdaining to be warded or concealed by any artifice. Its feet, observable beneath the ample folds of the garment, were also bare; and on its head it wore no other covering than a holly wreath, set here and there with shining icicles. Its dark brown curls were long and free: free as its genial face, its sparkling eye, its open hand, its cheery voice, its unconstrained demeanour, and its joyful air. Girded round its middle was an antique scabbard; but no sword was in it, and the ancient sheath was eaten up with rust.

And today in a shop I saw a large model of Father Christmas dressed in Blue. Times keep on changing.