‘"Costume, Tattoo, or Skin Condition?’ I vaguely remember the leg coverings like that but not in detail, was it very thinly decorated, so you couldn’t see what pattern it actually was?
These are a few of the current generation of the style. I remember many of the early ones being red, which meant that if you were watching a decorated leg poking in and out of the skirt, you'd be like, "Are those scabs? No, wait, they're sequins. Definitely sequins, because you probably wouldn't skin your leg in the same pattern as the bra."
If you search that store for "Venus Collection," you can see a few more variations. It looks like many of them now integrate the design all the way from the bra to the ankle. Pro: A long, continuous motif means you realize sooner that the leg markings are part of the costume design. Con: Now it looks like you wrapped a slightly-too-small-but-floor-length sheet of spandex over a decorated catsuit.