Examine source code of macFFox

{
  "name": "macFFox",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "toolbar": "rgba(238, 238, 238, 1)",
      "frame": "rgba(204, 204, 204, 1)",
      "tab_background_text": "rgba(89, 89, 89, 1)"
    }
  }
}