When customizing a switch, using a custom icon (example "power") and not providing any color the default switch is displayed. Is color a "must field"? Does that work as designed?
I would expect that the power icon is displayed (even without any color specified) and with a default color - maybe --nr-dashboard-widgetBackgroundColor for active.
What color is used for default icon, switched off?
when set custom - yes you currently have to set it fully custom both icon and colours. Yes it's working as designed - though Pull Requests are welcome.