After climax, the giver rips the drapes (curtains) off the wall and throws them over the receiver to show he is finished. Perhaps seen as derogatory to the receiver.
If a person wants to know if someone's pubic hair is the same color (or in some cases, same style) as the hair on their head, they might ask "Do the drapes match the carpet?" The drapes are hair; carpet is pubic hair. This is akin to asking "Is she a true blond?" Someone's obviously dyed hair might prompt this speculation: "I'll bet the drapes don't match the carpet."