The word is French and first described wool that had been neither bleached nor dyed; English took it up as a color name in 1887. In lingerie, beige is the older, plainer cousin of nude: a sandy, slightly yellow neutral used for shapewear, full-cup and minimiser bras, and support briefs.
Beige reads well under light-colored clothes on fair and light-olive skin. It is less flattering on display than pinker nudes, which is one reason fashion brands have moved toward names like sand, latte or skin. Cotton and microfiber both hold it evenly; in lace it can look flat unless paired with an ivory or gold trim.
The classifier places beige between nude, which is pinker, and tan, which is darker. Taupe shares the lightness but adds grey.