Yep, totally normal. My girl went blue 4 days ago and I haven't seen her since, except when I check on her. She's been under her water dish this whole time. They can't see well, they feel gross, it's completely understandable that they feel vulnerable so they want to hide.

I'm about to offer her some food, but I'm expecting it to be refused. Luckily my baby ball Tonks is a little savage, so she'll eat it if Ana Gwyn won't!