Examine source code of vivid sky

{
  "theme": {
    "images": {
      "theme_frame": "vividsky2.jpg"
    },
    "colors": {
      "frame": "#0c74f2",
      "tab_background_text": "#f7f7f7"
    }
  },
  "version": "2.0",
  "name": "vivid sky",
  "manifest_version": 2,
  "description": "a brightly colored cloudy sky"
}