I've looked in the color list for PRV but can't find a way to change the active track color.
Here track 2 is the active one but I'd like to make it a much more obvious (lighter) color.

 
Is it possible that it's listed somewhere in the color customization list under a less obvious name?

Thank you!

I'm afraid not. I suggest you submit a feature request when the new FR system is available.

Thanks!