Examine source code of Grapeshot

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Grapeshot",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-015-79a105bb546d3dfdd686392cf3ad1f57.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(124, 94, 195)",
      "toolbar_text": "rgb(183, 155, 249)",
      "frame": "rgb(46, 138, 109)",
      "tab_background_text": "rgb(213, 195, 253)",
      "toolbar_field": "rgb(158, 148, 180)",
      "toolbar_field_text": "rgb(90, 69, 140)",
      "tab_line": "rgb(161, 126, 245)",
      "popup": "rgb(119, 89, 192)",
      "popup_text": "rgb(69, 68, 75)",
      "button_background_active": "rgb(69, 13, 205)",
      "button_background_hover": "rgb(87, 48, 181)",
      "frame_inactive": "rgb(46, 138, 109)",
      "icons_attention": "rgb(69, 13, 205)",
      "icons": "rgb(213, 195, 253)",
      "ntp_background": "rgb(213, 195, 253)",
      "ntp_text": "rgb(69, 68, 75)",
      "popup_border": "rgb(161, 126, 245)",
      "popup_highlight_text": "rgb(213, 195, 253)",
      "popup_highlight": "rgb(46, 138, 109)",
      "sidebar_border": "rgb(34, 25, 77)",
      "tab_selected": "rgb(119, 89, 192)",
      "tab_loading": "rgb(161, 126, 245)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{95209e48-3f9e-4250-8327-c48cf531ddf5}"
    }
  }
}