In an earlier life I chose between light gray, medium gray and black as I felt some images were overpowered by a blinding white. I'm not sure why I switched to white over the years, since I don't show my work in enough other galleries to care what they think. I can't say that I'm unhappy with the switch, but I do believe there is something to be said for a good gray.
If you aren't afraid of rejection by the art world, try experimenting. I think from a purely aesthetic point of view, there is much to recommend such a choice. How wide your mat borders are also comes into play. In my gray years, I tended to use frames with only a couple of inches of mat. With the four inches or so I now use, I might not like the gray as much. Since many walls are white, a white mat and a thin frame seems to give more of an impression of the print floating on the wall.
There is a reason why Photoshop's F key cycles between a gray screen and a black one as a backdrop to pictures.