Examine source code of Hitclub

{
  "name": "Crystal",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "1000049586.jpg"
    },
    "colors": {
      "frame": "rgba(240, 204, 223, 1)",
      "tab_background_text": "rgba(120, 107, 107, 1)",
      "toolbar": "rgba(0, 0, 0, 0)",
      "toolbar_field": "rgba(0, 0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{98ba21df-15d2-4813-8368-ac35197d9a5e}"
    }
  }
}