Examine source code of Smooth

{
  "name": "Smooth",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "firefoxbkgr.png"
    },
    "colors": {
      "toolbar": "rgba(38, 38, 38, 0.15)",
      "toolbar_field": "rgba(0, 0, 255, 0)",
      "toolbar_field_text": "rgba(81, 104, 194, 0.76)",
      "frame": "rgba(255, 255, 255, 0.46)",
      "tab_background_text": "rgba(118, 64, 122, 1)",
      "bookmark_text": "rgba(79, 63, 143, 1)"
    }
  }
}