I have such a hodge-podge mix of supplies, paper and such, from so many different places. I've decided that the words "coordinating" and "complimentary" are much more worthwhile for me than "matching."
If the solid color cardstock I have on hand doesn't
exactly match the color in my patterened paper, I don't stress and worry about it. When the whole card is done, it usually looks pretty good. To me, at least.