green about the gills
Also, green around the gills. Looking ill or nauseated, as in After that bumpy ride she looked quite green about the gills. The use of green to describe an ailing person's complexion dates from about 1300, and gills has referred to the flesh around human jaws and ears since the 1600s. Although in the 1800s white and yellow were paired with gills to suggest illness, the alliterative green has survived them.