Examine source code of Tree Sky

{
  "theme": {
    "images": {
      "theme_frame": "treetops.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Tree Sky",
  "manifest_version": 2,
  "description": "This handmade piece is as if you are looking at the sky through a canopy of trees."
}