Examine source code of Grungy Circles

{
  "theme": {
    "images": {
      "theme_frame": "top.jpg"
    },
    "colors": {
      "frame": "#9e9e9e",
      "tab_background_text": "#a8a8a8"
    }
  },
  "version": "2.0",
  "name": "Grungy Circles",
  "manifest_version": 2,
  "description": "Darker theme with grungy circles highlighting parts of the header.  "
}