Uiappearance

UIAppearance

Intro

Implementation

Implement it in didFinishLaunching method of your app delegate or scene delegate.

UINavigationBar.appearance().barTintColor = .red

Resources

HWS | what-is-the-uiappearance-proxy

SO | UI appearance not working on programmatic UI

how-to-theme-an-ios-app-using-uiappearance

NSHipster | uiappearance

raywenderlich | uiappearance-tutorial-getting-started