d3.scale.category20() code example
Example: d3.scale.category20c v4
var colorScale_1 = d3.schemeCategory10;
var colorScale_2 = schemeCategory20;
var colorScale_3 = d3.schemeCategory20b;
var colorScale_4 = d3.schemeCategory20c;
var colorScale_1 = d3.schemeCategory10;
var colorScale_2 = schemeCategory20;
var colorScale_3 = d3.schemeCategory20b;
var colorScale_4 = d3.schemeCategory20c;