Some of the online companies have a "design board" in the shopping cart where you can see the swatches together, rearrange, etc. E-quilter is one.
What I often do is right click on the swatch (enlarge first if you can), save it on your desktop. I copy & paste all into PowerPoint and look at them together. That way, I can enlarge further, rearrange, add/delete until I find what I want.