I don't think it's a colour change thing since the new feathers that are growing are clean white just as before. And like I said, the dirtyness becomes apparent once she is soaking wet where the dirty feathers show their 'true colours' which is dirty dirty dirt grey.
Btw I have no idea what you mean with Dawn liquid dish. You mean general dish washing soap? It's ok to wash the bird with that but not with baby shampoo?
Is it ok to repost a picture from my other thread? ;P