I've never seen a Red Cap chick, but Red Caps are rose combed. Rose looks like pea comb at hatch, but does not have the distinct rows of bumps. There will either be no small bumps on the comb or they will have a random distribution. The rose comb is usually broader in the front, tapering to the back, than pea comb. Tell us the other types of chickens that you expect in the order and I may be able to tell you how to sort them out.
Many breeds have the same down colors.
The only ones we received alive were the speckled sussex, the buttercup, and one that we think is a barred Rock. We're not sure what the hatchery is going to do it about it yet, so guess we may just be out of luck. Anyway, Thanks again. I'm printing your message to keep for future reference. This time of the year you take your chances with chicks.