Examine source code of Dark Gray

{
  "manifest_version": 2,
  "version": "1.1",
  "name": "Dark Gray",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(54, 54, 54)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(54, 54, 54)",
      "popup": "rgb(42, 42, 42)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgba(0, 0, 0, 0.44)",
      "button_background_hover": "rgba(0, 0, 0, 0.44)",
      "icons_attention": "rgb(255, 255, 255)",
      "icons": "rgb(193, 193, 193)",
      "ntp_background": "rgb(0, 0, 0)",
      "popup_border": "rgb(54, 54, 54)",
      "popup_highlight": "rgb(54, 54, 54)",
      "sidebar_border": "rgb(54, 54, 54)",
      "sidebar": "rgb(42, 42, 42)",
      "tab_loading": "rgb(54, 54, 54)",
      "toolbar_field_border_focus": "rgba(34, 25, 77, 0)",
      "toolbar_field_border": "rgba(0, 255, 0, 0)",
      "toolbar_field_highlight": "rgb(54, 54, 54)",
      "toolbar_top_separator": "rgb(54, 54, 54)",
      "toolbar_vertical_separator": "rgb(54, 54, 54)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f5081c68-94e0-47d8-9b1d-fb4907f460b5}"
    }
  }
}