TabColorizer - Visual Environment Distinction Instantly identify which environment you're working in! TabColorizer adds customizable colored borders to websites, making it impossible to confuse your test, training, and production systems. ✨ Key Features

Smart Domain Matching - Supports wildcards (*.test.example.com), automatic www-matching, and root domain inclusion
5 Beautiful Themes - Choose from High Contrast, Nature, Industrial, Space, or Ocean with 15 colors each
Advanced Customization - Adjust border width (5-20px) and style (solid, dashed, dotted) per rule
Quick-Add Function - Add current domain with one click from the toolbar
Import/Export - Backup and share your rules as JSON files
Fully Accessible - WCAG 2.1 compliant with complete keyboard navigation and screen reader support
Multilingual - Available in English, German, French, and Spanish

🎯 Perfect For

Developers working with multiple environments
QA testers who need clear visual distinction
System administrators managing various servers
Anyone who wants to organize their browsing experience

🚀 How It Works

Click the TabColorizer icon in your toolbar
Add a domain and choose a color
The website instantly gets a colored border
Never confuse environments again!

📝 Example Rules

production.company.com → Red border (danger zone!)
staging.company.com → Yellow border (caution)
test.company.com → Green border (safe to test)
localhost → Blue border (local development)

Privacy First TabColorizer works completely offline. No data is collected, no analytics, no external connections. Your rules stay on your device. Open Source Developed with ❤️ for the Firefox community. Suggestions and feedback are always welcome!