CC Madhya 20.335
tretāra dharma ‘yajña’ karāya ‘rakta’-varṇa dhari’
“In Satya-yuga the people were generally advanced in spiritual knowledge and could meditate upon Kṛṣṇa very easily. The people’s occupational duty in Tretā-yuga was to perform great sacrifices. This was induced by the Personality of Godhead in His reddish incarnation.