Welcome to BYC, sorry this has to be a way to say hi.
Have you checked under her feathers looking for any type of injury? Are the colors you are seeing are they deep bruising? Any feather loss around the area? Is she able to eat and drink on her own? How is she acting, walking around normal chicken stuff. Or is she ruffling her feathers sitting not moving, tail down droopping her wings? What color is her poop? Is her crop full, empty, mushy or hard?
Does she have access to a compost pile? Can she have gotten into any old carcass or meat? Or old vegetation?
You need 10 posts to be able to post pictures, if possible make some other comments and post some pictures so others can see what you are dealing with it would help so much more. I personally have seen that before but was bruising from an attack it may not be the same as what you are dealing with.