Are you sure this is a return and not a supply? If it is a return hopefully have more of these since this is too small to be the only return.

Try to find a vent cover that has slats on an angle. Point the angle towards the wall. This will block most of the view when you looking down at it.

Thanks everyone! @mike_home it is a return. We have opened up the space around it and it is the only return...hopefully it's enough! I have had trouble finding grilles that identify having slats with angles. I will keep searching and check out the sites @diane r recommended.

If the issue is the ability to see the duct work below the grate, paint the duct flat black and use whatever grate you want. However, this will require more frequent cleaning. As dust settles against flat black, it will look light gray and make it stand out again.

Where is it in the space ? Is it possible to put a console table in the area.

Patricia, unfortunately it is in a space that would not easily accommodate a piece of furniture. @Wishiwereintheup, that is the issue and I will definitely paint the inside a flat black, good idea!