Marianne and Inge are spot on. However, I'll offer a different suggestion: Since wrap dresses CAN stand so well on their own (you can accessorize, but you really don't need to do much except add either a cami or a beautiful necklace), I'd advise against a neutral color, and would go either with a print or with a color that is one of your "signature colors" and flatters you really well.
I'm not against neutrals at all, but I'm not sure a dress is the right piece of clothing to purchase in a neutral color. A dress in a flattering color or print and a terrific cut can stand by itself and will never look boring or scream for the addition of an accessory.