Examine source code of Nighttime Dweller

{
  "theme": {
    "images": {
      "theme_frame": "butterfly.jpg"
    },
    "colors": {
      "frame": "#12064a",
      "tab_background_text": "#12064a"
    }
  },
  "version": "2.0",
  "name": "Nighttime Dweller",
  "manifest_version": 2,
  "description": "butterfly, night, nighttime, blue, pretty"
}