https://gmaps-samples-v3.googlecode.com/svn/trunk/styledmaps/wizard/index.html

style.json

[
  {
    "featureType": "poi",
    "stylers": [
      { "visibility": "off" }
    ]
  },{
    "featureType": "landscape",
    "elementType": "geometry.fill",
    "stylers": [
      { "lightness": 100 }
    ]
  },{
    "featureType": "road",
    "elementType": "geometry",
    "stylers": [
      { "invert_lightness": true },
      { "lightness": 80 },
      { "gamma": 1.57 },
      { "saturation": -24 }
    ]
  },{
    "featureType": "transit",
    "stylers": [
      { "visibility": "off" }
    ]
  },{
    "featureType": "water",
    "elementType": "geometry",
    "stylers": [
      { "color": "#d2ecff" }
    ]
  },{
    "featureType": "road.local",
    "elementType": "geometry",
    "stylers": [
      { "visibility": "simplified" },
      { "lightness": 44 },
      { "saturation": -69 }
    ]
  }
]