VTF Flags for Paint Tool impervious models

I am trying to create a model with two separate textures on it. One will be white and the other will be gray with brass elements as well. When using the paint tool on the model, I only want the white portions to be adjusted.

This is an object going into my game mode that will act as a container for different materials. To indicate which material it holds, I would like to color it. I don’t know how to do this but I think you’d have two separate textures and set a flag on one of them to use a different format that isn’t changed by the paint tool. Maybe a different shader than LightmappedGeneric? Or just a flag other than “8 Bit Alpha”?

Has anybody here tried this? I know it’s been done, but I have no idea how.

On the current branch the only way to do that is to give the white texture a white alpha channel, then the grey a black alpha channel

Then add $blendTintByBaseAlpha 1 to your vmt

I appreciate it. Thank you.