Examine source code of Doom Pulls the Strings

{
  "theme": {
    "images": {
      "theme_frame": "doom_allways_pulls_the_strings_mod.jpg"
    },
    "colors": {
      "frame": "#cf7070",
      "tab_background_text": "#fceded"
    }
  },
  "version": "2.0",
  "name": "Doom Pulls the Strings",
  "manifest_version": 2,
  "description": "Dr. Doom persona for firefox"
}