Examine source code of Opeth-Metal

{
  "theme": {
    "images": {
      "theme_frame": "FirefoxOpeth.JPG"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#bf0000"
    }
  },
  "version": "2.0",
  "name": "Opeth-Metal",
  "manifest_version": 2,
  "description": "para los fans del black y de opeth, para los sabios en el metal"
}