Examine source code of Copper Tubing

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Copper Tubing",
  "manifest_version": 2,
  "description": "Copper tubing theme to accent different layers on your browser. In this case, it's made for a menu bar, url box, bookmarks toolbar, and bottom tabs. Works well without the bookmarks toolbar as well."
}