River pant question (might be spoilers)

[ssshunt]

So the pants that River wears in The Big Bang have no back pockets and are made out of what looks like a heavy knit. Heavy-ish. I found a pant that looks very much like her pants but they have a seam with contrasting stitching across the butt. Argh. Other than that they look PERFECT. Or--should I tailor down a pair of somewhat thick (not flimsy, but very clingy) yoga pants that have no seams or pocket? Or should I keep looking? I thought the jeans I found would work, until I found the first pants I was talking about.

I could pick out the contrasting stitching and use brown thread instead, I suppose. Then it would not be so noticeable. OK, ok, I need to post a pic.