How do you get get rid of red paint/blood from feathers?

[bridgetchicken]

I rescued two white king pigeons from a live meat market and they have a red color on their feathers that are a red food coloring or perhaps dried blood. How do I remove the red color?

 

[JacinLarkwell]

I rescued two white king pigeons from a live meat market and they have a red color on their feathers that are a red food coloring or perhaps dried blood. How do I remove the red color?

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Usually it just has to just be molted out once it stains