Examine source code of Slatewall

{
  "theme": {
    "images": {
      "theme_frame": "slatehead.png"
    },
    "colors": {
      "frame": "#fc0303",
      "tab_background_text": "#fffb03"
    }
  },
  "version": "2.0",
  "name": "Slatewall",
  "manifest_version": 2,
  "description": "Taken from a wall on a 1950s office building in London, covered in Welsh green slate"
}