Examine source code of Clean Darkness

{
  "manifest_version": 2,
  "version": "1.1",
  "name": "Clean Darkness",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(16, 17, 17)",
      "toolbar_text": "rgb(238, 238, 238)",
      "frame": "rgb(16, 17, 17)",
      "tab_background_text": "rgb(238, 238, 238)",
      "toolbar_field": "rgb(26, 28, 29)",
      "toolbar_field_text": "rgb(238, 238, 238)",
      "tab_line": "rgba(60, 60, 60, 0.5)",
      "popup": "rgb(26, 28, 29)",
      "popup_text": "rgb(238, 238, 238)",
      "tab_selected": "rgba(255, 255, 255, 0.06)",
      "toolbar_bottom_separator": "rgba(60, 60, 60, 0)",
      "toolbar_field_border": "rgba(60, 60, 60, 0.5)",
      "toolbar_top_separator": "rgba(0, 0, 0, 0)",
      "tab_loading": "rgba(60, 60, 60, 0.5)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{88c59719-6c9e-41be-89ac-4c72dc58ed9a}"
    }
  }
}