What color/ coating for inside of sump?

I am redoing the stand for my new to me 120 gallon tank. My current tank is a 70 gallon, and when I redid that stand, I used a rubberized roof coating for the sump area. It worked out great, since I had a mishap and the sump over flowed. Not a single drop of water made it out of the stand. After I coated the stand, I painted it black.



So my question, on the new stand, what color should I go with? I really am shying away from the black. Right now its coated with the rubberized roof coating and primed grey. Since this tank will be in my living room, I wanted a more pleasing color if the sump area is opened to show it off to someone. I plan on having some nice plumbing with some colored PVC to go with whatever color I paint the inside.



I was thinking of spray painting the inside a grey like the primer but I'm not sure. Since this is my forever tank and stand, I want it to be perfect, but I am no interior designer.



So what are some opinions on a color theme? And pics are a plus!!



Thanks