deep roll of blue at the tops

Question

I want some help with my question about the meaning of “deep roll of blue at the tops”:

"The men were dressed in blue, of the same shade as their hats, and wore well-polished boots with a deep roll of blue at the tops." (The Wonderful Wizard of Oz - Chapter 2 - Describing the Munchkins)

Which part is the "top"? Is the roll like a curl over the toes? Or it could be also a cuff at the top of the shank, where the top of a boot will hit on the leg?

Answer 1

I couldn't find a blue one, but here's a roll top boot...