Examine source code of Dark Uniform V3

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Uniform V3",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(100, 98, 109)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(47, 45, 53)",
      "tab_background_text": "rgb(215, 226, 239)",
      "toolbar_field": "rgb(177, 212, 230)",
      "toolbar_field_text": "rgb(47, 45, 53)",
      "tab_line": "rgb(113, 124, 131)",
      "popup": "rgb(100, 98, 109)",
      "popup_text": "rgb(215, 226, 239)",
      "button_background_active": "rgb(142, 140, 150)",
      "button_background_hover": "rgb(54, 58, 89)",
      "icons_attention": "rgb(183, 230, 255)",
      "ntp_background": "rgb(115, 121, 125)",
      "ntp_text": "rgb(163, 224, 255)",
      "popup_border": "rgb(183, 230, 255)",
      "popup_highlight": "rgb(105, 120, 128)",
      "sidebar_highlight": "rgb(77, 100, 112)",
      "sidebar": "rgb(100, 98, 109)",
      "tab_loading": "rgb(110, 134, 149)",
      "tab_selected": "rgb(100, 98, 109)",
      "tab_text": "rgb(163, 224, 255)",
      "toolbar_bottom_separator": "rgb(84, 82, 91)",
      "toolbar_field_border_focus": "rgb(158, 206, 230)",
      "toolbar_field_border": "rgb(183, 230, 255)",
      "toolbar_field_focus": "rgb(164, 185, 198)",
      "toolbar_field_highlight_text": "rgb(255, 255, 255)",
      "toolbar_field_highlight": "rgb(93, 139, 162)",
      "toolbar_field_separator": "rgb(158, 206, 230)",
      "toolbar_field_text_focus": "rgb(98, 87, 140)",
      "toolbar_top_separator": "rgb(117, 116, 132)",
      "toolbar_vertical_separator": "rgb(127, 124, 138)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{426e8c1d-1dc9-48a5-85c8-f65af0033120}"
    }
  }
}