Compare them to ones without markings, look for consistencies, inconsistencies, pay attention to the minor details. Do all the keys feel the same way when you put them on your keyboard?? Do the topre CCs click/snap into place?? Are the colors where they're supposed to be??
Variations with the layering of candy corn and julysicles are normal. I know it's tough to have this level of scrutiny for CC, but given the price they're selling for, its important to understand what you are getting; even with major brands there are A grade products and B grade products and are usually priced accordingly, similar to F2s, they're all priced lower for more reasons than just the color.