Examine source code of Visiting Spaceman

{
  "theme": {
    "images": {
      "theme_frame": "justvisiting.jpg"
    },
    "colors": {
      "frame": "#de1818",
      "tab_background_text": "#471717"
    }
  },
  "version": "2.0",
  "name": "Visiting Spaceman",
  "manifest_version": 2,
  "description": "Little astronaut dropped in to say \"hi.\""
}