Etymology

Origin uncertain; likely of medieval (Scholastic) origin,^[1] particularly due to the grammar. An alternative, more recent form: de gustibus et coloribus non est disputandum ‎(“There’s no arguing about tastes and colors.”) originated in French literature in the early 1800s.

The sentiment behind the phrase is much older though. Plutarch reports that when Cæsar was dining at his friend Valerius Leo's in Milan, his host served up asparagus dressed in muron rather than olive oil. When his friends complained, Cæsar rebuked them:

‘ἢρκει γὰρ,’ ἔφη, ‘τὸ μὴ χρῆσθαι τοῖς ἀπαρέσκουσιν ὁ δὲ τὴν τοιαύτην ἀγροικίαν ἐξελέγχων αὐτός ἐστιν ἄγροικος.’
‘Surely,’ said [Cæsar], ‘it were enough not to eat what you don't like; but he who finds fault with ill-breeding like this is ill-bred himself.’ – Plut. Cæs. 17.6^[2]