Examine source code of Green Abstract Brushing

{
  "theme": {
    "images": {
      "theme_frame": "green_cloudbrushFFPersona_header.jpg"
    },
    "colors": {
      "frame": "#363636",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Green Abstract Brushing",
  "manifest_version": 2,
  "description": "I made some custom brushes in Photoshop and decided to try them out on a Firefox Persona. Hope you all enjoy."
}