Every theme you install is filed on the SD card together with the layouts it applied, so switching back to one needs no internet at all. Applying rewrites the layout of every screen that theme covers; Forget drops only the entry, never the artwork.

A theme is one published set: a wallpaper for every screen, the layout drawn against each of them, and the knob artwork it was drawn with. Installing converts the wallpapers to this panel's .bin on the SD card, files each layout as that wallpaper's preset, and applies all of it — so it needs a card. The knob lands on the card too, with its transparency intact, so it survives a reboot with nothing to re-download; screens whose layout leaves the knob unset keep the plain themed one.

The standard background for screens set to General. When an internet wallpaper is fetched (Internet tab), it replaces this on every General/Internet screen; screens set to a specific SD file keep it.

🎨 Edit gradient / solid colours in Settings ▸ Theme ▸

Applies to every wallpaper — per-screen SD files and the fetched internet one. Lower it to darken the image so on-screen text stays readable; gradient/solid backgrounds are not affected. 100% = original image.

Convert a PNG/JPG to an LVGL RGB565 .bin scaled to the current panel resolution and store it under /wallpapers/<width>x<height> on the SD card — without changing what any screen shows. Assign it later per screen with the 🗂 picker under the live preview.

The device downloads these PNGs itself and keeps them in RAM, so no SD card is involved and transparency is preserved. Point a widget's Knob image at asset0…asset3 instead of a file path. They are fetched in the same batch as the internet wallpapers and follow the Auto refresh setting on the Internet tab — with it Off, use Fetch now. Artwork is limited to 128×128 px of source image.

Convert a PNG/JPG to an LVGL .bin and store it on the SD card, then point a widget at it (e.g. a volume-slider Knob image). The image is scaled to the size selected during upload — for a knob, that is its on-screen size. PNG transparency is preserved (the file becomes RGB565A8); a JPEG or a fully opaque PNG stays the smaller RGB565. Unlike an asset slot this lives on the card, so it survives a reboot with nothing to re-download.

The device downloads a photo straight from the selected service (on that service's own terms) and uses it as the screen background, kept in RAM until reboot. A playing radio stream pauses during the download. NASA APOD API links are resolved automatically (DEMO_KEY is rate-limited — a free personal key from api.nasa.gov lifts that).

Each filled slot costs one screen-sized image in RAM and is re-downloaded after every reboot. Assign a slot to a screen in that screen's Background source.