House Sparrow with two-toned beak

So what’s going on with this sparrow’s beak? Breeding males have glossy black beaks, while females and immature birbs have different shades of brown and tan. Maybe this one is a dude in the process of changing from breeding to nonbreeding colours? I don’t really know.

   2 August 2022
   West End
   1/500s    f/5.6   400mm   ISO 160