Settings → Themes now has six color palettes to pick from, all sharing the same dark "scope screen" layout — only the trace colors change: Cyan/Amber, Phosphor Green, Amber Monochrome, Magenta Lab, Red Avionics, and Ice White. Pick one and it's remembered until you change it again.
Making it apply everywhere
The app's colors used to be hardcoded per screen. Making six switchable themes actually retint the whole app meant converting every screen's colors — background, surface, card, line, text, accent — to resolve through the selected theme at runtime instead of a fixed value. That touched 23 layout files, several drawables, and a handful of screens with custom-drawn graphics like the history graph and the coverage/DX maps.
The bug that shipped first
The first version only applied a new theme on the very next screen you opened — anything already on screen behind it, like the home screen sitting behind Settings, kept its old colors until you fully closed and reopened the app. Every screen now checks, each time it comes back into view, whether the saved theme has changed since it was built, and rebuilds itself if so. Picking a theme now retints everything that's open, not just what you open next.