Examine source code of Crab Flower

{
  "theme": {
    "images": {
      "theme_frame": "crabtree.jpg"
    },
    "colors": {
      "frame": "#4dd417",
      "tab_background_text": "#31e324"
    }
  },
  "version": "2.0",
  "name": "Crab Flower",
  "manifest_version": 2,
  "description": "Hope this Crab tree looks as good as it did last year."
}