Examine source code of Simple Purple

{
  "name": "Simple Purple",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "HammerHintergrund.jpg"
    },
    "colors": {
      "frame": "rgba(111, 0, 255, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(111, 0, 255, 1)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(77, 0, 255, 1)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(77, 0, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a72c4127-be28-4d7e-83ea-85ac7e08e0fe}"
    }
  }
}