Crow losing colour

I work in the middle of nowhere with lots of wildlife.

Short ver.

This crow had damaged feathers on its wing 6 months ago, now it’s right hand side is going white.

long ver.

there’s a Crow here that had an issue with its wing (some feathers had been damaged). I could not get anywhere close to it to look, so started feeding the birds to see if I could build up its strength. I have seen it get better, now able to fly high enough to perch on trees. Now the damaged feathers and even more have started to turn white.

Question: is this normal/healthy? If not, is there anything I can do?