Examine source code of Ursa Major

{
  "theme": {
    "images": {
      "theme_frame": "ursa_major_header.JPG"
    },
    "colors": {
      "frame": "#143300",
      "tab_background_text": "#00c700"
    }
  },
  "version": "2.0",
  "name": "Ursa Major",
  "manifest_version": 2,
  "description": "Stars and galaxies in Ursa Major"
}