Primary crow feathers should be fine for fletching. I'm not sure of the legality of using them though. There is an open hunting season on them so I assume they would be legal to use.
You will have to stick with the black because you won't be able to stain or bleach them.
You can wash them off with warm soapy water, shake the water out and lay them flat to dry. When dry they will look messed up but if you run them through the steam of a tea kettle they will come back to normal.