Examine source code of Composition

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Composition",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 0, 0, 0.73)",
      "toolbar_text": "rgb(236, 234, 230)",
      "frame": "rgb(236, 234, 230)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgb(236, 234, 230)",
      "toolbar_field_text": "rgb(0, 124, 94)",
      "tab_line": "rgb(0, 0, 0)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "button_background_active": "rgb(156, 0, 0)",
      "button_background_hover": "rgb(236, 234, 230)",
      "icons_attention": "rgb(255, 182, 54)",
      "icons": "rgb(255, 81, 81)",
      "ntp_background": "rgb(236, 234, 230)",
      "ntp_text": "rgb(0, 0, 0)",
      "popup_border": "rgb(0, 0, 0)",
      "popup_highlight": "rgba(66, 177, 53, 0.73)",
      "tab_background_separator": "rgb(175, 32, 0)",
      "tab_selected": "rgb(152, 40, 40)",
      "tab_text": "rgb(236, 234, 230)",
      "toolbar_bottom_separator": "rgb(181, 0, 0)",
      "toolbar_field_border_focus": "rgb(255, 0, 0)",
      "toolbar_field_border": "rgb(254, 143, 82)",
      "toolbar_field_highlight_text": "rgb(0, 0, 0)",
      "toolbar_field_highlight": "rgba(254, 254, 75, 0.75)",
      "toolbar_field_separator": "rgba(19, 135, 0, 0.73)",
      "toolbar_field_text_focus": "rgb(27, 75, 103)",
      "toolbar_top_separator": "rgba(188, 2, 2, 0.99)",
      "toolbar_vertical_separator": "rgb(255, 255, 255)",
      "tab_loading": "rgb(0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{48f2370e-1f17-424f-9f3b-4e10b4bda572}"
    }
  }
}