Examine source code of Dark Doom

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Doom",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(17, 5, 5, 0.88)",
      "toolbar_text": "rgb(234, 219, 221)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(207, 181, 181)",
      "toolbar_field": "rgb(4, 0, 0)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(189, 5, 5)",
      "popup": "rgb(45, 27, 27)",
      "popup_text": "rgb(212, 212, 212)",
      "ntp_background": "rgb(26, 13, 13)",
      "tab_loading": "rgba(119, 30, 30, 0.88)"
    }
  }
}