Examine source code of Resting Crocs

{
  "theme": {
    "images": {
      "theme_frame": "croc-firefox.jpg"
    },
    "colors": {
      "frame": "#a2db99",
      "tab_background_text": "#b7d9ab"
    }
  },
  "version": "2.0",
  "name": "Resting Crocs",
  "manifest_version": 2,
  "description": "Crocs resting. Underwater perspective."
}