Examine source code of TabTint

{
  "manifest_version": 3,
  "name": "__MSG_extensionName__",
  "version": "1.4.0",
  "description": "__MSG_extensionDescription__",
  "default_locale": "en",
  "permissions": [
    "tabs",
    "storage",
    "activeTab",
    "contextMenus",
    "alarms"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background/service-worker.js"
    ],
    "type": "module"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tabtint@yavuz.extension",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_title": "TabTint"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "styles/tab-line.css"
      ],
      "js": [
        "content/content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com;"
  },
  "commands": {
    "color-red": {
      "suggested_key": {
        "default": "Alt+1"
      },
      "description": "Apply Red"
    },
    "color-blue": {
      "suggested_key": {
        "default": "Alt+2"
      },
      "description": "Apply Blue"
    },
    "color-green": {
      "suggested_key": {
        "default": "Alt+3"
      },
      "description": "Apply Green"
    },
    "remove-color": {
      "suggested_key": {
        "default": "Alt+0"
      },
      "description": "Remove Color"
    }
  }
}