Examine source code of decorative seashells

{
  "manifest_version": 2,
  "name": "decorative seashells",
  "version": "1.2",
  "description": "custom theme for Firefox",
  "theme": {
    "images": {
      "theme_frame": "images/header.jpg"
    },
    "colors": {
      "toolbar_field": "#ffffff",
      "toolbar_text": "white",
      "icons": "white",
      "tab_background_text": "white",
      "toolbar": "rgba(4, 12, 29, .3)",
      "frame": "#040c1d"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b6ffd936-f101-44a1-9598-ed16612ca17d}"
    }
  }
}