Examine source code of Swimmers

{
  "theme": {
    "images": {
      "theme_frame": "Swimmers.jpg"
    },
    "colors": {
      "frame": "#0d2682",
      "tab_background_text": "#ffb2b2"
    }
  },
  "version": "2.0",
  "name": "Swimmers",
  "manifest_version": 2,
  "description": "Here are a bunch of identical swimmers in blue bikinis swimming across your toolbar."
}