Examine source code of Steam Power

{
  "theme": {
    "images": {
      "theme_frame": "header_steam2.png"
    },
    "colors": {
      "frame": "#525252",
      "tab_background_text": "#bababa"
    }
  },
  "version": "2.0",
  "name": "Steam Power",
  "manifest_version": 2,
  "description": "Like that hideous Steam* Ui? want it in your browser? here ya go! :D\n\n* Steam is a copyright of vALVE software."
}