A friend said I looked green around the gills.

一个朋友说我看上去green around the gills(吓得脸都绿了)。

Being "green around the gills" is looking pale and sickly.

“满鳃发绿(green around the gills)”表示面色苍白，体弱多病。

You should sit down. You look a bit green around the gills .

你应该坐会儿，你看起来脸色很不好。