Virtually any shade of grey complements black but my advice to you is bring in another bold accent color like red, yellow or turquoise because grey and black is chilly and kind of "bachelor pad"

What was used on the ceiling? I have a small room 12' x14- and would like to add something like this-

http://www.benjaminmoore.com/en-us/paint-color/throughthelookingglass, http://www.benjaminmoore.com/en-us/paint-color/elephantgray or http://www.benjaminmoore.com/en-us/paint-color/touchofgray from Benjamin Moore or you can use https://www.sherwin-williams.com/visualizer/# to get the colors shown in the room from Sherwin Williams. Dark red, fuchsia or pale pink, violet, lavender, lilac, or sky blue would look nice with gray and black.

The ceiling here is a painted punched tin ceiling.

Upper left hand corner . . . is the crown molding missing ?
What would be the reason for this ? Looks unfinished.

Darlene, the tin ceiling has a crown that runs all the way around the room, so it's not missing anywhere. The fireplace breast extends into the space about 8" or so, this may be the portion that you are referring to at the ceiling.

Aaaahaaa! Indeed it is. My bad. An optical illusion for me . . . I enlarged the photo and see it clearly now. Thanks.

I have white sofa pale grey walls with accents of aqua and green - who is manufacturer of the side chairs or name of material? As grey is hard to match, I found a real shaggy rug with mixes of white & aqua as it looked better on light maple floors. They also had other colors.