Android 5.0 Lollipop introduced the ability to specify theme overrides directly on individual Views using android:theme. This post explains the difference between themes (global styling) and styles (view-level styling), how ContextThemeWrapper underlies theme overlays, and how ThemeOverlay.Material variants work. Practical examples show how to apply a dark theme to a Toolbar and how to use a custom ThemeOverlay to set theme attributes like colorEdgeEffect on a single view. AppCompat backports android:theme support for Toolbar on older API levels.
