{
  "version": 8,
  "sources": {
    "vector": {
      "type": "vector",
      "url": "https://demotiles.maplibre.org/tiles/tiles.json"
    }
  },
  "layers": [
    {
      "id": "minimum",
      "type": "fill",
      "source": "vector",
      "source-layer": "layer",
      "paint": {
        "fill-color": [1,2,3],
        "fill-outline-color": "not a color"
      }
    },
    {
      "id": "ops",
      "type": "fill",
      "source": "vector",
      "source-layer": "layer",
      "paint": {
        "fill-outline-color": ["darken", 10, "#FF0000"]
      }
    }
  ]
}