canary has an odd grey/purple spot above anus

by Barb
(n.y.c)

i was cleaning my female canaries feathers near her anus because she had a little solid feces stuck there. she's still been able to have bowl movements, the feces weren't stopping anything. it just wasn't sanitary. i believe this was caused by her new food.

But my question is, when i was cleaning her feathers i noticed there was a greyish purple spot directly above her anus. Its about the size of a dime. it didn't appear to cause no pain when i touch it, and it wasn't swollen. She appears to be perfectly healthy aside from the spot. she's eating and drinking. her energy seems fine as well. Is there anything i should be seriously worried about, any reason i should take her to see an avian vet?