Tbh, it gets a lot messier than that, and there are much better examples.
It would be great if the Lycanthropy Gems actually had some kind of circle around them, to make a board smattered with a mix of Skulls/Doomskulls and Lyc. Gems less confusing.
If necessary, maybe a brief, little, dull flash around the Gem as it’s changed from Purple to Lycanthropy could be added to highlight it, so it won’t be missed.
The first time I saw it, I immediately tried to match with skulls. Thought my game was broken. …I even knew it was supposed to be purple gems but in the moment, forgot. Whoops.
Next time guess what, I was like… Why is this not matching with skulls?! …oh. right. Purple.
OTOH though that would make lyco gems less visually distinct from the purple gems, so less easy to spot them quickly when they do appear.
(For me the visual cue is white = skull; I get thrown off by some of the holiday skulls that add color to the skull design, especially the St. Patrick’s Day one that adds a lot of green.)
If they had made them so they could be matched with either purple gems or with skulls that would have been more interesting… maybe interesting enough to make dealing with lycanthropy worthwhile… nah.