Examine source code of Dirt McGurk

{
  "name": "Dirt McGurk",
  "manifest_version": 2,
  "version": "4.0",
  "theme": {
    "images": {
      "theme_frame": "fftheme2.png"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(0, 0, 0, 0.6)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(110, 110, 110, 0.35)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 162, 31, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{798bf415-ab0e-4abd-9639-646bc0c28782}"
    }
  }
}