THE LAYER MANAGER HAS A COLUMN THAT ALLOWS YOU TO CHANGE THE COLOR AND LINE WIEGHT IN A VIEW PORT.

MY QUESTION: HOW DO I MAKE A PARTICULAR LAYER A LIGHT GREY SHADE IN ONE VIEW PORT AND NOT CHANGE IT IN ANOTHER LAYER?
FOR EXAMPLE: I WANT THE WALLS ON MY FLOOR PLAN TO BE DARK AND I WANT THE WALLS FOR MY ELECTRICAL PLAN TO BE A LIGHT GREY.

I believe you have to place them on separate layers. I find that using separate layers for different entities makes life a lot easier later on in the design.
The ability to switch layers off can often clarify things.

From what I can figure out, you have to have a Viewport selected, then select the particular layers in the Design Director that you want to change, then pick a color from the "VP Color" column. Select another Viewport and repeat, but choose a different color. Changes seem to only affect the VP that is selected. Right-click on the Printer icon to see what the Page Setup preview looks like, to see what has changed.

When done with this setup, select the layers in the Design Director, right-click and choose "Remove Viewport Overrides for…", pick a choice (i.e. All Layers / In All Viewports) to return everything to normal.

From what I can figure out, you have to have a Viewport selected, then select the particular layers in the Design Director that you want to change, then pick a color from the "VP Color" column. Select another Viewport and repeat, but choose a different color. Changes seem to only affect the VP that is selected. Right-click on the Printer icon to see what the Page Setup preview looks like, to see what has changed.

When done with this setup, select the layers in the Design Director, right-click and choose "Remove Viewport Overrides for…", pick a choice (i.e. All Layers / In All Viewports) to return everything to normal.

I'll be damned... If I were a full-time architectural draftsperson, that'd come in really, really, handy.
That resolves two mysteries for me.