Examine source code of Really Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Real Dark",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(19, 19, 19)",
      "toolbar_text": "rgb(203, 196, 196)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(188, 188, 188)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgba(17, 17, 17, 0.57)",
      "popup": "rgb(21, 21, 21)",
      "popup_text": "rgb(227, 227, 227)",
      "button_background_active": "rgb(0, 0, 0)",
      "button_background_hover": "rgba(0, 0, 0, 0.29)",
      "icons_attention": "rgb(252, 252, 252)",
      "icons": "rgb(181, 181, 181)",
      "ntp_background": "rgb(15, 15, 15)",
      "popup_highlight_text": "rgb(255, 255, 255)",
      "popup_highlight": "rgb(40, 40, 40)",
      "tab_loading": "rgb(185, 185, 185)",
      "tab_selected": "rgb(51, 51, 51)",
      "tab_text": "rgb(255, 255, 255)",
      "toolbar_field_border_focus": "rgb(90, 90, 90)",
      "toolbar_field_border": "rgb(0, 0, 0)",
      "toolbar_field_highlight_text": "rgb(0, 0, 0)",
      "toolbar_field_highlight": "rgb(108, 108, 108)",
      "toolbar_field_separator": "rgb(0, 0, 0)",
      "toolbar_field_text_focus": "rgb(212, 212, 212)",
      "toolbar_top_separator": "rgb(0, 0, 0)",
      "toolbar_vertical_separator": "rgb(60, 60, 60)"
    }
  }
}