Examine source code of River Otter

{
  "theme": {
    "images": {
      "theme_frame": "otter_persona_2.jpg"
    },
    "colors": {
      "frame": "#6da8a2",
      "tab_background_text": "#8cb3a9"
    }
  },
  "version": "2.0",
  "name": "River Otter",
  "manifest_version": 2,
  "description": "River otter rock rocks otters"
}