went nuts for weeks trying to find a black/white stripe for a workshop. NOBODY had one. went to Joann's last Friday & low & behold! there it was! too late!

A pretty real pink and a true deep purple.

I just bought some hunter green at JoAnn's. I thought I was buying black! But I found a use for it already so am glad I bought it.

The right shade of purple has been my latest nightmare. Purples are out there in droves but the one I needed to match looked like washed out pink next to 99.9% of the purples I found.

the bright "neon" colors in quilting fabric seem impossible to find and I don't want to make kites!

I agree on this. Also, this applies to both blues and greens -- I find that blending blues or greens is most difficult because one blue may have too much green or too much red in it; same with greens -- one green may have too much (or not enough) yellow, blue or brown. Does all this mumbo-jumbo make any sense?

Red is the one for me, I was looking and looking and finally
found one that matched what I needed got it home started
cutting to realize, it wasn't all cotton...well I used it anyway.
I broke the cardinal rule...I hope it will be okay.

Try sewing a simple block using the fabrics. Steam press the gazoobas out of it. If the part-cotton one does OK, it'll be fine. I once pieced something using cottons and blends. When I gave the really serious steam press to the piece, one of the pieces really drew up (perhaps melted a bit). Lesson learned.

Like fabrics with black backgrounds, but the print has to be vivid, or Victorian.

Yes I agree it is always the color or design you are looking for. As soon as you finish your project you can find it everywhere.