Examine source code of Sympathy Colors

{
  "theme": {
    "images": {
      "theme_frame": "Firefoxpersona2.jpg"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#f9f9fa"
    }
  },
  "version": "2.0",
  "name": "Sympathy Colors",
  "manifest_version": 2,
  "description": "A little thing I whipped up in Microsoft Paint."
}