It looks dyed. Perhaps Heteractis crispa (sebae). Provide bright light and regular, small feedings of squid, shrimp, silversides, etc. to try and get it to regrow the zooxanthellae (algae) that should be living in its tissue. Hopefully, this anemone will take on a brownish, tan color which indicates its populations of zooxanthellae are being recolonized. Most of this anemones nutritional needs are met by the algae that live in their tissue.
Gary