Gray theme background when starting Zoom Meeting

Hello, I'm here to ask if anyone has the issue where, when you join the meeting, and you have set Zoom on dark mode, apparently the color surrounding my webcam is gray, when I want it all black.

Is there a way to get rid of the gray box around my camera? I can link/show a screenshot of it so you can see what I mean by it.

Example of the issue I'm talking about.