So You're Buying a New Carpet?
MOST WOULD SAY: "Blue"
SOME WOULD SAY: "Beige" or "Off White"
SOME MIGHT EVEN SAY: "Gold"
Remember that when you fall in love with a particular color, the best way to 'flatter' it is to surround it not with itself, but with a complimenting color that will cause it to pop out and be noticed.
There is no 'right' or 'wrong' in this situation; it's all about the mood you want to create and the lighting that will make or break your placement of color in a room with a beautiful piece of carpeting like this here.
The architecture for that room will also help direct which color(s) and where to place them.
I can guarantee you one thing with a carpet like this: if ONE accent wall were to be completed in a warm, rich reddish brown color, that would be a striking compliment that would cause the blues, caramel and golden color in this piece to really be showcased. Red tends to anchor other things in a room. It can certainly stand on its own as a strong accent, but when placed in a room with warm, soft colors that are surrounded by creamy warm off-whites, the red would be an anchor point that can make the entire room feel like a complete project.
Warning: watch for clashing use of other reds in the area (like picture frames). Best to stick with rich brown finishes.