Examine source code of Scratched Metal

{
  "theme": {
    "images": {
      "theme_frame": "rat2.jpg"
    },
    "colors": {
      "frame": "#3b3b3b",
      "tab_background_text": "#5c5c5c"
    }
  },
  "version": "2.0",
  "name": "Scratched Metal",
  "manifest_version": 2,
  "description": "It's metal...and it's scratched"
}