Shiva Purana
एकविंशतिमः कल्पः पीतवासा इति स्मृतः ॥ ब्रह्मा यत्र महाभागः पीतवासा बभूव ह ॥१७॥
The twenty-first Kalpa is said to be Pītavāsas wherein Brahmā of great achievement became yellow-robed.
english translation
ekaviMzatimaH kalpaH pItavAsA iti smRtaH ॥ brahmA yatra mahAbhAgaH pItavAsA babhUva ha ॥17॥
hk transliteration by Sanscript