@Green Witch,
I'm not always matchy, as match can get under my skin sometimes. I also have scads of rugs, some of them cheapos and a few of some value, and move them around. (We used to have a gallery down the street that also sold rugs - deep downfall for me, as we got a good discount.) So my criterion would be not that the rug was a paint chip match, but that it wouldn't fight with the curtains. The rug might, say, go with the furniture or the wood in the room, say some combo of browns, and not have a curtain color in it. A rug can be - a painting on the floor, eyecatcher, or underlying textural and color interest. (This reminds me of my purple, orange, and black rug from Mexico City.. what was I thinking? But I wish I still had it.)