Examine source code of Darcula Theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Darcula",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(50, 50, 50)",
      "toolbar_text": "rgb(187, 187, 187)",
      "frame": "rgb(43, 43, 43)",
      "tab_background_text": "rgb(128, 128, 128)",
      "toolbar_field": "rgb(35, 37, 37)",
      "toolbar_field_text": "rgb(187, 187, 187)",
      "tab_line": "rgb(70, 72, 74)",
      "popup": "rgb(43, 43, 43)",
      "popup_text": "rgb(187, 187, 187)",
      "tab_selected": "rgb(70, 72, 74)",
      "tab_text": "rgb(187, 187, 187)",
      "tab_loading": "rgb(70, 72, 74)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9b411a5c-3d04-4fa8-911d-2c24e42a3a07}"
    }
  }
}