The page isnt public yet, so I don’t know how to show you, but if I choose a background color or image, I see that instead of the suggested white/grey/black backgrounds on the demo.
Nevermind. Figured out that widget areas 10-13 and the slider (the only ones I was using) had a transparent background, not grey. So my whole site was grey. Recreated the 4 widget areas in a white widget area using a text widget and it works fine.