Inspection flap for natural stone masonry exterior?

Hello,

currently a granite wall is being built for me in the outdoor area. A small door for a revision matter is to be installed in this wall. It doesn't have to be sealed, just a simple door.

What options are there for this? When I google [Revisionsklappen], only flaps for the chimney in indoor areas come up.

Would there possibly be something that could be clad so that the door doesn’t stand out so much?

If I google for revision flaps

Then add "outside" to the search. There is a full range from plastic to stainless steel in various sizes. Covering is not known to me. So that there are matching flaps.