Change the look of the Gauge (Speedometer) 2.0 component

[misdashboards]

I am using the Gauge component included in the Scn extension. I was wondering if there is a way I can change the look of the gauge. I tried to create a css class for it to change the font type, but it isn't working. I also want to change the color of the outline or border, but it's not responding to css. I hope I am using the wrong css properties. I am attaching a screenshot for reference.

Thank you for your help.