Examine source code of Black nigth

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Black nigth",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-005-f5f3cf677b1f132c75ddc7bd319dd1fc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(68, 45, 238)",
      "toolbar_text": "rgb(67, 194, 218)",
      "frame": "rgb(14, 41, 65)",
      "tab_background_text": "rgb(24, 156, 180)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(67, 194, 218)",
      "tab_line": "rgb(33, 86, 96)",
      "popup": "rgb(7, 50, 84)",
      "popup_text": "rgb(243, 245, 247)",
      "button_background_hover": "rgb(6, 6, 6)",
      "icons_attention": "rgb(59, 36, 44)",
      "icons": "rgb(0, 0, 0)",
      "ntp_background": "rgb(74, 68, 70)",
      "tab_loading": "rgb(33, 86, 96)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4203a81f-1527-4561-80a5-d0528a6aebcf}"
    }
  }
}