Effectively selecting colors for your choropleth map can be intimidating. Thankfully there are a couple of resources that can help us out.

The first is the [ColorBrewer](http://www.colorbrewer.org/) website which allows you to tinker with a preset or custom color pallette over a live map.

The second is a preconstructed D3 Map from the mbostock library that contains pre-defined colors, constructed using ColorBrewer.

http://mbostock.github.io/d3/talk/20111018/choropleth.html