How To Fix A Dead Tooth Color. This is similar to a crown you may get after a root canal, but it is designed for cosmetic purposes. A dead tooth no longer has a living nerve in it and so will likely feel different to a living tooth.
Best option would be to have root canal on this 'dead' tooth and internally whiten to see if the color can be brought to match the others. Do nothing and simply live with the color. First, the root canal area needs to be accessed.
It's important to see your dentist because they'll know how to stop tooth decay from spreading.
With that being said, one dark tooth can really be an esthetic problem, so doing a prophylactic root canal. Dead tooth smell (bad breath) and swelling around the gums. It’s important to see a dentist if you have any of these signs. Pulp removal, or a root canal, may actually reverse the color change.