URL Bar Color Rules by Andrey

Give each website or development environment its own address bar colors, so you can tell them apart at a glance.

• Customize both the background and text colors.
• Choose colors with the color picker or enter HEX codes.
• Use automatic contrast to keep text readable.
• Match websites with simple masks: example.com for a site, .example.com for its subdomains, or example.com/admin/ for a section.
• Use * for any number of characters and ? for one character. No regular expressions required.
• Choose Hostname RegExp (advanced) when you need regular expressions. Existing rules keep working as before.
• Arrange rules by priority—the first matching rule applies.
• Set default colors for pages that do not match any rule.
• Colors update automatically when you navigate, switch tabs, or save settings.
• Each Firefox window uses colors for its own active tab.
• Open the extension popup to see the current hostname, matching rule, and colors.

Getting started:

1. Click the extension icon, then Configure rules.
2. Add a rule, keep URL mask (simple) selected, enter a mask such as example.com, and choose your colors.
3. Click Save settings.

Privacy:

• All rules are checked locally.
• Settings stay in your Firefox profile.
• No accounts, tracking, analytics, or network requests.

Firefox limitations:

• The same colors also affect the Find in Page field (Ctrl+F).
• Applying colors may change parts of your current theme, including its background image.
• Other extensions that change the browser theme may interfere with these colors.