Hi, I thought I'd try color masking but ran into some issues.
Question 
#1To get results like this:

do you make multiple materials just to change a color like this? Does anyone know how effective are the draw calls for 3+ materials with the same textures in them? (example below)
 I tried looking online to see if there was a different way but they all showed how to apply different materials to one mesh.

Question 
#2To color mask in unreal can I use the RGB channels or just black and white for each part I want to change colors? 
I must have missed something but here are my results:

and here is where I made the texture linear color:

Question 
#3Why did my RMA mask not work? 
How it turned out:

and here is what I was going for minus the texture blur:

As always, thanks.