Mr Sun ... Shine your light on me.

I bet you have tried to print a shaded view of lets say floor layouts/patterns, and struggled endlessly with trying to match the pantone colours. It just doesn't come together.
When turning to "shaded with edges", Revit (and most 3D apps) makes use of default sun light that shines down on your model, giving it a slight edge and depth. (Mr. Sun, Mr. Golden Sun, shine your light on me….jingle…..daughter + Barney all day long)

To get an accurate portrayal of the real pantone colour rather select a solid surface pattern for your material. The surface pattern will show in a normal hidden line view.
In the views you don’t require the surface colour to be visible for floors, switch it off in visibility graphics.