kṛṣṇa-dhyāna - meditation upon Kṛṣṇa; kare - perform; loka - the people; jñāna-adhikārī - who are advanced in spiritual knowledge; tretāra - of Tretā-yuga; dharma - the occupational duty; yajña - performance of sacrifices; karāya - induces; rakta-varṇa dhari' - assuming a reddish color.

“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.