So how is it done?
Regardless of how its done, it clearly uses a method prohibited by the developers.
I think the point is to say that the developers are lying saying "it cant be done" as they have told several color blind players.
It can clearly be done. if you they don't want modders fixing it, they should implement it.
As a professional programmer, it is nothing but time to make this (or any feature) happen, they are not willing to invest the time.
How the video maker did it, or how quickly they will ban him for making his game more player friendly is irreverent. the point is that it CAN be done and they are unwilling to put in the effort.