Examine source code of darkenberry

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "darkenberry",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(83, 83, 83)",
      "toolbar_text": "rgb(239, 234, 255)",
      "frame": "rgb(38, 38, 38)",
      "tab_background_text": "rgb(239, 234, 255)",
      "toolbar_field": "rgb(32, 32, 32)",
      "toolbar_field_text": "rgb(239, 234, 255)",
      "tab_line": "rgb(255, 130, 171)",
      "popup": "rgb(32, 32, 32)",
      "popup_text": "rgb(239, 234, 255)",
      "button_background_hover": "rgb(192, 52, 98)",
      "popup_highlight": "rgb(64, 64, 64)",
      "tab_selected": "rgb(192, 52, 98)",
      "tab_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(255, 130, 171)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ddc452fb-67f6-4d3b-b8dd-fdea2e093431}"
    }
  }
}