Examine source code of PropIcon

{
  "theme": {
    "images": {
      "theme_frame": "PropFireFox.jpg"
    },
    "colors": {
      "frame": "#67a7d8",
      "tab_background_text": "#595a5e"
    }
  },
  "version": "2.0",
  "name": "PropIcon",
  "manifest_version": 2,
  "description": "Propagate Persona"
}