白沙在涅，与之俱黑

Explanation: Nirvana: black. Mixed black and white natural sand black. Good in a bad analogy environment, will gradually deteriorate 　　Usage: Complex sentence; for clause; containing derogatory 　　Source: Qin Xun "Xunzi Encouraging Learning": "white sand in the Line, with which all black. Lan Chih-Huai is the root, and its getting the Respecting Truth, the gentleman does not close, common people against."