May be too early to tell, but here is what happened.
Smashed my finger in a door about a month ago.
The finger got really swollen, and there was some bleeding under the nail (so the nail turned dark red - almost black near the cuticle)

The swelling has pretty much gone down
The dark red part of the nail is moving forward (like the nail is growing)
Between the red part and the cuticle, the nail is now kind of yellow-gray.

I don't mind if this nail falls off & another one grows. But I am wonderng if I damage the part of the nail so that it may not grow back ?

What should I look for ? ow can I tell what will happen.

May be too early to tell, but here is what happened.
Smashed my finger in a door about a month ago.
The finger got really swollen, and there was some bleeding under the nail (so the nail turned dark red - almost black near the cuticle)

The swelling has pretty much gone down
The dark red part of the nail is moving forward (like the nail is growing)
Between the red part and the cuticle, the nail is now kind of yellow-gray.

I don't mind if this nail falls off & another one grows. But I am wonderng if I damage the part of the nail so that it may not grow back ?

What should I look for ? ow can I tell what will happen.

You already answered your own question when you stated "Between the red part and the cuticle, the nail is now kind of yellow-gray." Unless the nail was ripped out by the root, a new nai lwill emerge. It will not look very good at first, but it will get better as the nail bed heals. the damaged portion will be pushed off the free edge as the new nail plate cells emerge.

Sounds good.

Thanks for the help