Radial gauge (Tachometer etc.) with two colors

I'm wondering how to split a radial gauge into two color zones, where if the gauge reaches the "redline" the color doesn't change on the entire gauge, but instead has a color change when inside the redline zone. Basically I'm trying to make a Forza Motorsport style overlay for SimHub based on Forza Motorsport 7, and the tachometer in that game has two color "zones" where if the tach reaches the redline, the gauge splits into a second part with orange instead of the normal gray