When the great sage Narada was chanting the glories of the Lord, the bluish line on the neck of Lord Siva disappeared. Upon seeing this, Gauri, the wife of Lord Siva, suspected Lord Siva of being someone else disguised as her husband, and out of fear she immediately left his company. Upon hearing the chanting of Krsna's name, Lord Balarama saw that His dress had become white, although He was generally accustomed to a bluish dress. And the cowherd girls saw all of the water of the Yamuna River turn into milk, so they began to churn it into butter. In other words, by the spreading of Krsna consciousness, or the glories of Krsna, everything became white and pure.

From NoD ch. 43.