Is the abnormal color and shape of fingernails related to health?

Yes, it can be judged from the change of nail color and shape and crescent white.

Crescent white seems to be related to qi and blood. Generally speaking, the hand should have a standard shape with a good and moderate radian. Eight white crescent moons are standard health (there are no little finger crescent moons in both hands), and some little fingers are prone to coronary heart disease.