I've been trying to figure out why my skirts have been changing colors while I'm walking and sometimes during idle movements (oddly enough, not while jumping). I chatted with a staff member sugarQb about this a few tests ago but we never figured out exactly what was causing the technicolor skirts, though I believe it was forwarded to another team eventually. The skirts change color based on skin color, hair color, type of pants, type of shoes, etc.
During the last downtime I changed my hairstyle from my usual onion head hairstyle (#20 counting left to right including "none") to a different hairstyle and when the game came back up I figured the bug had been resolved until I went back to trusty ol' onion head... turns out the blink tag still exists on my skirts!
I have tried on every hairstyle and the onion head is the only one that makes my skirts blink.
Thanks to Feral Kitty for helping!
Edit: It's most noticeable on the fuller or layered skirts like "Blueberry Layered Skirt" and "Summer Picnic Skirt"
TLDR: Skirts blink while walking and idle motions while wearing onion head hairstyle.