Examine source code of Bewitched...

{
  "name": "Bewitched...",
  "manifest_version": 2,
  "version": "5.0",
  "theme": {
    "images": {
      "theme_frame": "BewitchedHcopy.jpg"
    },
    "colors": {
      "frame": "rgba(58, 74, 31, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(57, 74, 30, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(57, 74, 30, 0.04)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(166, 255, 233, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{cff6f8f2-e18a-40fa-a9a8-a4d370d6e242}"
    }
  }
}