Duck head turning yellow?

[Magnolia Ducks]

I wonder what could've stained like that. I tried the grandma method of just licking my finger and trying to rub out the stain, but nothing. Only thing I could imagine would do that is if she like fell asleep with her head in a pile of her own poo

I hope you didn't lick your finger twice.....

 

[SolarDuck]

Its about the same amount of yellow on her head still. And now I noticed some on her angel wing. I don't have any dandelions in my yard.

 

[SolarDuck]

If it is a stain, how the hecc do I get rid of it?

 

[Magnolia Ducks]

I would not worry about it. She's very cute.