IPA: /ʌnˈpeɪntɪd/
KK: /ʌnˈpeɪntɪd/
Not covered with paint; in its natural state without any color applied.
The unpainted fence looked rustic and natural in the garden.
Unpainted → It is formed from "un-" (meaning not) and "painted" (from the Old French "peint", meaning to apply color). The word "unpainted" means not having been applied with color or paint.
Think of 'not' ('un-') having 'color applied' ('painted') — that's why unpainted means something that hasn't been painted.