Quote - Not .5, but 5. The luminance of the white rectangles is hyper-white 5.

Need to have my prescription checked. I could have sworn it said .5. Which didn't make sense.

Ambient_value of 5... does this make white a super-colour? Well, how can it? 1 x 5... what the heck colour is THAT? Or are we not changing WHITE itself, but the behaviour of that channel?
Opening a can of worms...

BTW, this is what I was talking about in that other thread about "Basic Poser Node Behaviour"... THIS needs to be accessible somewhere central...

[EDIT] Dang, cross-posted...

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks