Examine source code of Ready for Summer

{
  "name": "Ready for Summer",
  "manifest_version": 2,
  "version": "4.0",
  "theme": {
    "images": {
      "theme_frame": "ReadyforSummerHcopyCustom.jpg"
    },
    "colors": {
      "frame": "rgba(167, 140, 112, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(168, 142, 113, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(168, 142, 113, 0.08)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7612f5ea-b926-4c9e-b182-ac2bc0002999}"
    }
  }
}