Gris Firefox extension to toggle grayscale on websites

What it does

Click the extension icon to set the current website to grayscale. Click again to turn it off. Grayscale domains are stored on local storage, and re-applies automatically.

Features

• Simple
• Auditable
• Works

Local Install

Load it in Firefox:

1. Go to about:debugging
2. Click "This Firefox"
3. Click "Load Temporary Add-on"
4. Select manifest.json

How it works

• Injects filter: grayscale(100%) CSS on the domain
• Stores enabled domains in local storage
• Auto-applies the filter when you navigate to saved domains