Examine source code of Christmas24

{
  "name": "Christmas24",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Christmas24.jpg"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 0.95)",
      "tab_background_text": "rgba(1, 38, 90, 1)",
      "toolbar": "rgba(255, 255, 255, 0.58)",
      "toolbar_field": "rgba(187, 196, 240, 0.61)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6dbb4514-852e-43c3-ab28-4282ec7dca37}"
    }
  }
}