• Yellow: Mostly due to overuse of dark nail paints, simply skip nail paint for a bit. When you apply, use a clear base. In some cases, yellow nails can have other causes. “A fungal infection can cause severe yellowness and thickened nails,” says Dr Sethi. This can be treated by a topical cream or an oral tablet prescribed by the doctor. In rare cases, though, yellow nails can also occur due to an underlying health condition like diabetes or liver issues, explains Dr Sethi.
  • Green: A sign of an infection that needs medical attention. “This needs to be treated with antibiotics or a solution that comprises one percent acetic acid,” she says.
  • Brown or black: If the nail bed goes dark in patches or the whole goes black, it could be frequent injury or inflammation. “When your nail develops a dark line, however, it may be a sign of melanonychia. If benign, there is nothing to be done. In rare cases it can mean melanoma or skin cancer, which indicates a need of biopsy and removal of the lesion,” warns Dr Sethi.