I wouldn't purchase the sample card again. I have a sample card and I still had an issue with differences in dye lots to the point where a midnight blue became a really dark purple which was a nightmare for trying to get my daughters school dresses made in time with all the back and forth on purchasing fabric and getting the wrong colour.

For your red, I would go with their colour "red". It's the closest to a primary red.

Fabric.com will also allow you to return fabric at no cost. I recently purchased 5 different fabrics when I needed 3 but I wasn't sure which I wanted; I returned the 2 that didn't work. No problem. I love dealing with them.

I order all my solids from MSQC. When you receive them they come with the color code on them. I leave that label on the plastic baggie or the fabric so that if I need more, I can use that # to reorder. I also add the color and manufacturer to the label to make it even easier to identify.