The story
Phrase appears as early as 1830 according to OED. From rose-color or rose-colored (meaning "pleasant"), from the notion that roses are widely regarded as uncommonly beautiful.
Etymology from Wiktionary, CC BY-SA 4.0.
rose-colored glasses
Today it means: A cognitive or perceptual bias where an individual views something in an overly optimistic or positive light, often failing to recognize its negative aspects. Full definition →