Grey walls allow you the option of being bold in your color scheme or soft and relaxing. Either can be achieved with your selection of furniture. If you want modern and bold, shop for furniture that makes a statement in bright hues, reds, shocking pink, etc. For a more relaxed feel, I would suggest cream, pale shades of coral or antique rose. What ever you choose get what you like to look at everyday for a while, you can change your walls a lot cheaper and more often than you can the furniture.
We used a butterscotch (leather) sofa, plum wing back chairs (reupholstered) and throw pillows with the butterscotch and plum in an ikat design on the sofa.....the other furniture in the room is dark brown wood. A beautiful orchid plant in white looks great and matches the ceiling...also a large potted green plant on the floor about 3ft tall...
I would go Black, Silver and Glass for a really modern feel, then you can just pop the room with colour in your cushions, rugs and wall hangings.I am feeling for tones of orange at the minute or you could go with the tried and tested Red, however that is a bit predictable. This way you can change the pop colour whenever you feel like it.
Blacks, whites, and Ivories with hints of colors on the walls, pillows, accessories, etc. This way your room can have a modern, elegant look that's not plain. It's your room. Make it the way you want and envision it, and I'm sure it will turn out great.
You should go ahead with gold.
I painted my living room and dinning room with slate gray paint, painted all the woodwork high gloss white and laid red carpet. It looks wonderful, bold, modern, clean and fits together well.