Nails may be colored in colors other than the colors of the paint that women use for adornment. Rather, they may be colors that indicate a specific disease or health defect.       Blue nails, for example, may mean swollen lungs, a lack of oxygen in the blood, and a high percentage of abnormal hemoglobin in the blood.       And dark, black nails may mean anemia, vitamin B12 deficiency, nail bacteria infection, chronic liver disease or chronic kidney disease, and silver deposits in the nails.       White nails mean the presence of anemia, kidney and…