Hi @Bert_Leatherman,
Thanks for the post. The iOS SDK does not support dark mode at the moment. You could explicitly compile the app with light mode only(https://stackoverflow.com/questions/56537855/is-it-possible-to-opt-out-of-dark-mode-on-ios-13) or you could build the app with Xcode 10.
The yes,no, go slower,etc. icons in the Zoom default UI cannot be removed at the moment.
Hope this helps. Thanks!