Examine source code of Horsehead Nebula

{
  "theme": {
    "images": {
      "theme_frame": "HorseheadNebulaHeader.png"
    },
    "colors": {
      "frame": "#7a7a7a",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Horsehead Nebula",
  "manifest_version": 2,
  "description": "A beautiful portion of the Horsehead Nebula in the constellation Orion. \nCredit: NOAO/AURA/NSF"
}