Recolor for Firefox by Bhizie

Firefox Recolor replaces the plain background of websites with a wallpaper image.

• Works on every site, with hand-tuned styles for YouTube and YouTube Music.
• Light sites are switched to a dark look so they match the wallpaper; photos and videos keep their normal colors.
• Headers, sidebars and panels become translucent and blurred so the wallpaper shows through.
• Click the toolbar button to open the upload page, then drag and drop your own image (PNG, JPEG or WebP) to replace the wallpaper on all open tabs instantly.

Purely visual: it doesn't change how sites work, makes no network requests, and collects no data. Your uploaded image is stored only in the extension's local storage.