Examine source code of Arrowhead Rules

{
  "theme": {
    "images": {
      "theme_frame": "arrowheadrules.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ff0000"
    }
  },
  "version": "2.0",
  "name": "Arrowhead Rules",
  "manifest_version": 2,
  "description": "Kansas City Chiefs"
}