Quote -

The setup you quoted in your question didn't use the Diffuse_Color input. It used the Diffuse_Value input. That's the input that affects brightness while leaving color alone.

The next one I showed, not the one you quoted, had the shadow color trick and was plugged into the Diffuse_Color input instead, because I wanted to change brightness and color.

Which are you asking about really - something already in Diffuse_Color or something already in Diffuse_Value?

BagginsBill,

Apologies; I did get a little mixed up with what I was asking, there.  You have answered my question, though.  Thank you for posting your material room settings.  It's much easier for me to understand that way. :)