Facial feathers turning reddish brown

by Michael
(Smyrna,DE)

Hello there, I have had my little purple budgie (Chirppy) for almost a year now and she has been a delight to have around! Even though she is female, she chirps a lot (hence the name) and is very active like a normal birdie!

But lately her feathers on either side of her beak (normally white) and now just yesterday on her forehead also have turned a slight reddish brownish color! I know birds will try to hide illnesses for as long as possible but she doesnt show any behaviorial differences...right now she is roosting on one leg (a good sign) but she also appears a little more fluffed out than usual and a little more often too (but not a whole lot).

My question is this though, it didnt start happening until after I changed her main diet to Kaytee Fiesta Max Parakeet blend (comes in a red bag) which before her main diet was the pet shop parakeet seed blend that they sell by the pound where we bought her at as well.

Could there be a dye in this new food that is causing this? Or maybe its an allergic reaction to an ingredient(s)? Or is she sick/getting sick? I can provide pictures if need be!! I just dont want to lose my little Chirppy!!