I just watched this recently, one of the best Kurosawa films (Seven Samurai bored me to tears).
The throne room walls are decorated in this fascinating style, a minimal representation of clouds. Probably with gold, though hard to tell in black and white.
Does anyone know more about this art style? Is there a name for it?
Gilded clouds seem to be a common motif in Japanese art, as seen in this folding screen, which I made into a pocket square.