Work uses Google Meet and when I’ve got a few meetings, I keep the home page on my second screen. To avoid the cycling of backgrounds in my peripheral vision, I use this bookmarklet.

javascript:( (d) => {
    d.querySelector( '.q9EjXc' ).style.visibility="hidden";
    d.querySelector('.yvv8Re.OAburf').style.backgroundColor='black';
    d.querySelector('.l4V7wb.Fxmcue').style.display="none";
} )(window.document);