Examine source code of yotsugi ononoki

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "yotsugi ononoki",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right bottom"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(35, 167, 120)",
      "toolbar_text": "rgb(253, 165, 78)",
      "frame": "rgb(153, 182, 118)",
      "tab_background_text": "rgb(81, 216, 212)",
      "toolbar_field": "rgb(81, 216, 212)",
      "toolbar_field_text": "rgb(253, 165, 78)",
      "tab_line": "rgb(253, 165, 78)",
      "popup": "rgb(153, 182, 118)",
      "popup_text": "rgb(35, 167, 120)",
      "tab_loading": "rgb(253, 165, 78)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3c2a68b2-8fd2-41e5-8b64-68f2de31872e}"
    }
  }
}