That sounds good to me. When I do these sort of things in a space it can be a good idea to cut out a piece of kraft paper. Make a mockup of 16x23 and six of them. If you dont have paper to do this you can always do the same thing with painters tape. Then you know exactly how it will look in the space. Put them up on the wall with the 3" spacing and see if you need to change it. In terms of color I think the distressed white frames against a greenish/grey wall would look good.

I bought these and they look beautiful above my new ivory leather couch...did the walls in grey/green paint, Shiitake was the colour by Valspar. Very happy with the result. Thanks for the help!

Love these! Especially with the vintage looking frames. I say go for it! :)

Very nice! Ideally you should have at least 2/3 the length of your sofa, which would be 60 inches. You may want to buy another pair? Do your mock-up like RM & Company suggests.