श्रेष्ठानां पाण्डु श्वेतं चाप्राप्तकम् ॥ कZ_०२.१३.०५ ॥
śreṣṭhānāṃ pāṇḍu śvetaṃ cāprāptakam
For the best grade, pale or whitish coloration is unacceptable (it indicates deficiency/impurity).
Because discoloration signals alloying or impurity; explicit rejection rules protect the mint’s integrity and stabilize currency/treasury value.