Examine source code of Steampunk Firefox

{
  "theme": {
    "images": {
      "theme_frame": "Header.jpg"
    },
    "colors": {
      "frame": "#c7c7c7",
      "tab_background_text": "#573917"
    }
  },
  "version": "2.0",
  "name": "Steampunk Firefox",
  "manifest_version": 2,
  "description": "Just something I threw together for myself, wondered if anyone else would enjoy it. I used some brushes I found at DeviantArt forever-ago and don't remember who made them. If anything in here offends the original artist I apologize just email me and I'll remove it. \nOtherwise, thanks for downloading it!"
}