Examine source code of Double Mushrooms

{
  "theme": {
    "images": {
      "theme_frame": "doublemush1.jpg"
    },
    "colors": {
      "frame": "#8bf20c",
      "tab_background_text": "#fcf40d"
    }
  },
  "version": "2.0",
  "name": "Double Mushrooms",
  "manifest_version": 2,
  "description": "some mushrooms my kid found in our brook"
}