Ice-boy brings up a point... I see specular set at 3 and above in existing shaders. Obviously the originator of the shader was after a specific effect. Would you like an example of what I mean?

Colours for reflection or specular: they need gamma-correcting as well, don't they?

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