Examine source code of Crab Nebula 2

{
  "theme": {
    "images": {
      "theme_frame": "CrabNebula.jpg"
    },
    "colors": {
      "frame": "#080000",
      "tab_background_text": "#f7f4f4"
    }
  },
  "version": "2.0",
  "name": "Crab Nebula 2",
  "manifest_version": 2,
  "description": "Crab Nebula photo by NASA and image creation using \"Bryce\" ray-tracing program.\nSee more from PeakPixels on our YouTube channel."
}