Examine source code of Christmas Eve

{
  "theme": {
    "images": {
      "theme_frame": "ChristmasEve.jpg"
    },
    "colors": {
      "frame": "#7d7b7b",
      "tab_background_text": "#8f8b8b"
    }
  },
  "version": "2.0",
  "name": "Christmas Eve",
  "manifest_version": 2
}