Examine source code of Christmas Moose

{
  "theme": {
    "images": {
      "theme_frame": "HeaderChristmasMoose.jpg"
    },
    "colors": {
      "frame": "#e7d1b7",
      "tab_background_text": "#5e1416"
    }
  },
  "version": "2.0",
  "name": "Christmas Moose",
  "manifest_version": 2,
  "description": "Merry Christ-moose!"
}