Examine source code of Sinwell

{
  "theme": {
    "images": {
      "theme_frame": "GW2Necroheadder.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#080707"
    }
  },
  "version": "2.0",
  "name": "Sinwell",
  "manifest_version": 2,
  "description": "well i play a necro on Guild Wars and am really looking forward to Guild Wars 2 and yes you guessed it I'm making a necro."
}