天灰得像哭过海蓝得像洗过
[tiān huī dé xiàng kū guò hăi lán dé xiàng xĭ guò]
This nickname paints a vivid picture contrasting the gray sky, as if it has cried, with the clean and refreshing blue sea. It implies sadness or emotional cleansing juxtaposed with tranquility or peace.