YouTube Sigma by ATLAS GHOST

Sigma Cyberpunk restyles YouTube with neon glow colors, wallpaper backgrounds and a slimmer layout. It all runs locally in your browser, and you can tweak everything live from the toolbar popup.

Features

Presets: More than 1,000 ready-made looks. Search them, star favorites, shuffle a random one, and preview any look by hovering. Use the arrow keys to browse and Enter to load.
Wallpapers: Pick from bundled wallpaper categories, use your own image URL, or import a whole folder of images from a GitHub repo. Adjust the background opacity to taste.
Theme colors: Choose from a large list of curated color pairs, or set your own two colors. You can flip them, and the text color and glow follow the theme.
Logo: Replace the logo text and set its font size, spacing, brightness, glow and position. Match the theme colors, pick a pair, or choose custom ones. Style presets and your own saved styles are included.
Progress bar and player: Style the progress bar and slider colors, and tune the inner and outer player glow.
Slimmer layout: The Mix / up-next panel matches your theme, and YouTube gets a sensible default page zoom.
Backup: Export all your settings to a file and import them on another browser or computer.

Privacy
The extension collects no data and sends nothing to any server. Settings are stored in your browser's local storage. The only network request it makes is when you choose to import wallpapers from a GitHub link you paste.

Permissions

Storage: saves your settings.
youtube.com: applies the theme to YouTube pages.
GitHub (api.github.com and raw.githubusercontent.com): only used by the optional wallpaper import.