Set bubble transparency in Highcharts?

Question

Is there a way to influence the transparency of the bubbles in Highcharts bubble charts? I was looking for a configuration comparable to area fillColor, but didn't find one.

I tried using rgba colors for the series, like so:

       series: [{
        color: "rgba(255,0,0,0.5)",
        data: [ 

but that only made the border semi transparent.

Edit: I just tried to use marker fillColor:

series: [{
        color: "rgba(255,0,0,1)",
        marker: {
            fillColor: "rgba(255,0,0,0.1)"
        },

but that doesn't influence the transparency

Answer 1

You can use fillOpacity parameter,

marker: {
          fillOpacity:0.3
        }

http://jsfiddle.net/g8JcL/116/

Answer 2

The easiest way would be adding a CSS property.

.highcharts-point {
    fill-opacity: 0.8;
  }

But this will be applied to all the bubbles.