color helper — Martin

⚠️ Important: After installation, navigate to a regular website (not the addons.mozilla.org page or the Add-On Manager), then click the icon once and confirm the permission. If the error message persists, please restart your browser. I am VERY sorry but apparently this is the way it is supposed to work with Firefox 😔

Screenshot the current viewport, a selected area or a specific element on the page and inspect the color shades and approximate color names of the pixels.

Click on the extension icon for different methods of selecting pixels to inspect

✔️ 100% free and open source
✔️ Highly customizable
✔️ All processing is done locally
✔️ Free of tracking, analytics or ads
✔️ Does not break websites

Source and more Information: https://github.com/Mtillmann/color-helper-extension