Examine source code of Endless sky

{
  "theme": {
    "images": {
      "theme_frame": "33.jpg"
    },
    "colors": {
      "frame": "#0b45d9",
      "tab_background_text": "#1f0770"
    }
  },
  "version": "2.0",
  "name": "Endless sky",
  "manifest_version": 2
}