late 14c., prymrose, a name given to several plants that flower in early spring, earlier primerole (early 14c.), from Old French primerose, primerole (12c.) and directly from Medieval Latin prima rosa, literally "first rose" (see prime (adj.)). As the name of a pale yellow color, by 1844.
The parallel name primula (c. 1100) is from Medieval Latin primula "primrose," shortened from primula veris "firstling of spring," thus properly fem. of Latin primulus, diminutive of primus; but primerole was used in Old French and Middle English of other flowers (cowslips, field daisies). The primrose path is from "Hamlet" I, iii.