A hedge between keeps friendship green.
君子之交淡如水.
The pot calls the kettle black.
At night,all cats are grey.
猫在夜晚皆灰色(美丑好坏 暗中难分辨)
Care brings grey hair.
忧虑催人老.
Kill the goose that laid the golden egg.
杀鸡取卵.
True blue will never stain.
真金不怕火炼.（经得起考验）
The grass is greener on the other side.
得不到的更诱人.
The devil is not so black as he is painted.
魔鬼不像所描绘的那么黑（言过其实）
An evening red and a morning grey,is a sign of a fair day.
晚霞红如火,晓色青如灰,定是晴朗天.
After black clouds,clear weather.
否极泰来.