[Solved]-Highcharts - How to set a gradient theme for each type of graph globally?-Highcharts

You can achieve the desired result by using setOptions again like this:

Highcharts.setOptions({
  plotOptions: {
    line: {
        //color: Highcharts.getOptions().colors[0] - by default
    },
    spline: {
        color: Highcharts.getOptions().colors[1]
    },      
    column: {
        color: Highcharts.getOptions().colors[2]
    }, 
    pie: {
        color: Highcharts.getOptions().colors[3]
    }
  }
});

plotOptions.{your series type} describes default options for every series of the given type.

Live demo: http://jsfiddle.net/BlackLabel/d68m2qq8/