Changing Bar Chart Colours

I have read a lot of topics about people wanting to change the colour of their Charts but couldn’t find a definitive answer.
So I went to play, and I am a novice coder, to say the least.

Anyway, I got one of my bar chart items to change color with the .css code, not sure it is the best way either.

#kn-report-view_364-1 g.highcharts-series.highcharts-series-0.highcharts-tracker rect {
fill: rgb(100,200,100)


The only problem is the legend doesn’t change with it.
The element looks to be

#kn-report-view_364-1 g.highlights-legend-item rect {
fill: rgb(100,200,100)
but that doesn’t seem to work as I can’t tell it which legend item to update.
Is there a better element to change or how can I get the legend to change to the same color?

Any help is greatly appreciated.