White Nails
If the nails are mostly white with darker rims, this can indicate liver problems, such as hepatitis. In this image, you can see the fingers are also jaundiced, another sign of liver trouble.
Yellow Nails
One of the most common causes of yellow nails is a fungal infection. As the infection worsens, the nail bed may retract, and nails may thicken and crumble. In rare cases, yellow nails can indicate a more serious condition such as severe thyroid disease, lung disease, diabetes or psoriasis.