Examine source code of Yordle Painter

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Yordle Painter",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(113, 71, 50, 0.48)",
      "toolbar_text": "rgb(251, 203, 184)",
      "frame": "rgb(199, 143, 76)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgba(227, 204, 192, 0.59)",
      "toolbar_field_text": "rgb(234, 198, 179)",
      "tab_line": "rgb(255, 152, 126)",
      "popup": "rgb(117, 69, 49)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(255, 152, 126)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2bb06d58-5eeb-436b-b9ca-4cb83c753a60}"
    }
  }
}