Examine source code of Overwatch by M♥Donna

{
  "name": "Overwatch by M♥Donna",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Overwatch.jpg"
    },
    "colors": {
      "frame": "rgba(218, 216, 217, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(219, 216, 218, 0)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(219, 216, 218, 0.1)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(117, 38, 35, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c5d827d9-09a6-4daa-8106-9af1bc88fc7e}"
    }
  }
}