Examine source code of griddle2

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "griddle2",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 0, 0, 0)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(34, 40, 49)",
      "tab_background_text": "rgb(220, 220, 220)",
      "toolbar_field": "rgba(195, 126, 76, 0.91)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(195, 126, 76)",
      "popup": "rgba(49, 52, 58, 0.9)",
      "popup_text": "rgb(220, 220, 220)",
      "frame_inactive": "rgb(34, 40, 49)",
      "tab_loading": "rgb(195, 126, 76)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d34e4d45-2993-47c7-8379-ea9942296243}"
    }
  }
}