Sample json created using Google Maps Styling Wizard

overlay.json

[
  {
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#ebe3cd"
      }
    ]
  },
  {
    "elementType": "labels.text.fill",
    "stylers": [
      {
        "color": "#523735"
      }
    ]
  },
  {
    "elementType": "labels.text.stroke",
    "stylers": [
      {
        "color": "#f5f1e6"
      }
    ]
  },
  {
    "featureType": "administrative",
    "elementType": "geometry.stroke",
    "stylers": [
      {
        "color": "#c9b2a6"
      }
    ]
  },
  {
    "featureType": "administrative.land_parcel",
    "elementType": "geometry.stroke",
    "stylers": [
      {
        "color": "#dcd2be"
      }
    ]
  },
  {
    "featureType": "administrative.land_parcel",
    "elementType": "labels.text.fill",
    "stylers": [
      {
        "color": "#ae9e90"
      }
    ]
  },
  {
    "featureType": "landscape.natural",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#dfd2ae"
      }
    ]
  },
  {
    "featureType": "poi",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#dfd2ae"
      }
    ]
  },
  {
    "featureType": "poi",
    "elementType": "labels.text.fill",
    "stylers": [
      {
        "color": "#93817c"
      }
    ]
  },
  {
    "featureType": "poi.park",
    "elementType": "geometry.fill",
    "stylers": [
      {
        "color": "#a5b076"
      }
    ]
  },
  {
    "featureType": "poi.park",
    "elementType": "labels.text.fill",
    "stylers": [
      {
        "color": "#447530"
      }
    ]
  },
  {
    "featureType": "road",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#f5f1e6"
      }
    ]
  },
  {
    "featureType": "road.arterial",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#fdfcf8"
      }
    ]
  },
  {
    "featureType": "road.highway",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#f8c967"
      }
    ]
  },
  {
    "featureType": "road.highway",
    "elementType": "geometry.stroke",
    "stylers": [
      {
        "color": "#e9bc62"
      }
    ]
  },
  {
    "featureType": "road.highway.controlled_access",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#e98d58"
      }
    ]
  },
  {
    "featureType": "road.highway.controlled_access",
    "elementType": "geometry.stroke",
    "stylers": [
      {
        "color": "#db8555"
      }
    ]
  },
  {
    "featureType": "road.local",
    "elementType": "labels.text.fill",
    "stylers": [
      {
        "color": "#806b63"
      }
    ]
  },
  {
    "featureType": "transit.line",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#dfd2ae"
      }
    ]
  },
  {
    "featureType": "transit.line",
    "elementType": "labels.text.fill",
    "stylers": [
      {
        "color": "#8f7d77"
      }
    ]
  },
  {
    "featureType": "transit.line",
    "elementType": "labels.text.stroke",
    "stylers": [
      {
        "color": "#ebe3cd"
      }
    ]
  },
  {
    "featureType": "transit.station",
    "elementType": "geometry",
    "stylers": [
      {
        "color": "#dfd2ae"
      }
    ]
  },
  {
    "featureType": "water",
    "elementType": "geometry.fill",
    "stylers": [
      {
        "color": "#b9d3c2"
      }
    ]
  },
  {
    "featureType": "water",
    "elementType": "labels.text.fill",
    "stylers": [
      {
        "color": "#92998d"
      }
    ]
  }
]