20 looks that don't ship with the app, grouped by theme. Download a file, import it in Settings, and the calendar sheet is redrawn in that palette — paper colour, ink, texture and all.
.lunayatheme file you just saved.Installed themes sit next to the built-in ones and can be removed at any time. Nothing is sent anywhere — importing reads the file on your device.
A theme is a small JSON file: a palette, a paper texture, corner radii, and optionally a different arrangement of the blocks on the day sheet. Each download above has its source JSON beside it — take one, change the colours, and import it the same way. The full guide lists every colour token, every limit, and every error code, read straight from the app's own spec.