Examine source code of Tab Color Labels

{
  "manifest_version": 2,
  "name": "Tab Color Labels",
  "version": "1.0",
  "description": "Mark your tabs with color labels to stay organized. Click the toolbar button to pick a color for the current tab.",
  "author": "DigitaBuddy",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.png",
      "96": "icons/icon-96.png"
    },
    "default_title": "Tab Color Labels",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-color-labels@digitabuddy",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}