Tachometer Mechanic Ring - Material Bug?

I think there is a bug with the 'Tachometer Mechanic Ring' material.

The color graduations slider does not change the color of the font like all of its matching 'Mechanic Ring' materials (speedometer and fuel gauges) instead, it only changes the color of the ring.

I wanted to use this as emissive and cannot because the intensity of the font if much too high and cannot be adjusted, since none of the technical parameters seem to affect the font color/intensity either.