Looks like is was green and then they bleached it… idk much more on care but carpets are hard to keep healthy and with with powerful lights it’s hard to balance and find what works for these guys.
There are a couple others with carpet nems you might try looking up care after they have been bleached.
Def looks like a bleached green to me. Would need a couple small feedings a week to get back to where it needs to be. Small feedings being the key. If you purchase or have I recommend a QT with cipro or other antibiotic.