I'm having an issue cloning some hats with version 121 of the CustomizationItemClone tool. It effects the following hats/masks (that I've tried): Safeword Special, High Noon, Witch Hat, Zinyak Mask, Apocalyptic Goggles, and Santa Hat. Some hats I've tried that had no issues: Elf Hat, Murderbrawl Mask, Skeleton Mask, Country Straw Hat, Killbane.
On the Safeword Special and the High Noon hat it changes the secondary color to 0/0/0 RGB that is uncolorable. On the other hats/masks it makes things glow oddly. These two pictures show items that I cloned and uploaded without making any changes.
A workaround is opening the original file, copying the contents of the .str2_pc, renaming them to the cloned item names, and then repacking them.