Very worried - possible poison issue

I was away for a week and my cat sitter fed my cat wet food from an old ceramic bowl I use for dyeing my hair. Is it possible my cat was harmed? She seems fine but she is 16, has crf and hyperthyroid, gets methimazole 2x per day and is on prescription crf diet (Hills K/d and Royal Canin).

Cats can ingest many things that are harmful to us, there digestive system works differently. That is why they can drink from filthy bird baths and mud puddles with no harm, but onions, garlic, and milk can harm them. It is most likely too late to do anything about your problem now, monitor her closely and watch for vomiting, tremors, or excessive sleeping, I would call my vet and ask for advise. There are poison control centers out there for animals too, the number to one of them is 888-426-4435. The amount of dye left in the bowl was probably minimal, and I know how a 16 year old cat eats, so I think you'll be OK. I'll pray for your little one, bless you for being so concerned. 

Thanks so much. She doesn't eat much wet food but I told the sitter to put water in it as that encourages her to eat more...she has 6 bowls, two each for dry, wet and water (just in case since she drinks so much, is finicky, and air in home is very dry). I never imagined anyone would go searching in cabinets for other bowls...the hair dye bowl was not with other dishes.