There is no built in option, but you can use wpdatachart callbacks. Every chart exposes several options that customize its look and feel. Charts usually support custom options appropriate to that visualization. You can use it for adding options that are available in Highcharts API. In this callback in method wpDataChartsCallbacks 15 is id of the chart which you want to change colors.We used hex color codes with some random colors, but you can change it for your needs. There are six of them(if you have six series) if you had it more then you have to add more colors in colors array, separated with comma(except last one). On the end insert this script above shortcode of your chart on page.

<script type="text/javascript">
jQuery(window).on('load',function(){
    if( typeof wpDataChartsCallbacks == 'undefined' ){ wpDataChartsCallbacks = {}; }
    wpDataChartsCallbacks[15] = function(obj){
        obj.options.plotOptions.pie = {
            colors: [
                    '#50B432',
                    '#ED561B',
                    '#DDDF00',
                    '#24CBE5',
                    '#64E572',
                    '#FF9655'
            ],
            dataLabels: {
                    format: '{point.name}{point.percentage:.1f} %'
           }
        }
    }
});
</script>