Removing Overlay/Changing Opacity on Photos

Hello,

I don’t like how my images look dark on the following grids:

Big Grid Full 1
Big Grid Full 2
Big Grid Full 3

How can I remove the overlay (?), or whatever it is that is making the pics appear darker than they really are.

Also, on mobile, when I click the menu, there is a semi-transparent black box that covers the screen and my text is also black. How can I change this? Would prefer the box be white with red text

Thanks