In one of my apps I’m using “Allow five views in the bottom navigation bar” with dark theme. This is out of necessity because I need to hide the menu view. The app is used to log reports outdoors in the desert sun. Except for the button that is the active view, the nav bar buttons are gray and cannot be seen at all with sunglasses on.
I suggest you make the button backgrounds white instead of gray, as is the case with your 3 button nav bar. What’s more important in the app that being able to see the nav buttons?