Red modulator-Red vcv??
 

Is there a difference between red modulators and say black or even green? and how about red vcv's?
Just wandering.

According to the shop manual there were changes made as time went by to the modulator valves, the different ones are identifiable by their color.

I understand the red modulators were used on early 123's, they would adjust both the harshness and length of time each gear was involved. The green ones were just harshness, the Bowden cable decided how long each gear is in play.
I am unaware of a black one, or a red VCV.