Examine source code of Xmas Holly

{
  "theme": {
    "images": {
      "theme_frame": "XmasHolly.jpg"
    },
    "colors": {
      "frame": "#b4b4b4",
      "tab_background_text": "#99ff99"
    }
  },
  "version": "2.0",
  "name": "Xmas Holly",
  "manifest_version": 2,
  "description": "In many western cultures, holly is a traditional Christmas decoration, used especially in wreaths."
}