The futility of decorating a pig leads to more than one phrase. For example, trying to dress a pig in a gown only ruins the gown and annoys the pig. Or “you can’t make a silk purse from a sow’s ear,” which dates back at least to the mid-16th century. But today I looked at putting lipstick on a pig – the futile attempt to make superficial changes that don’t fool anyone.
Slate’s Explainer says A Classical Dictionary of the Vulgar Tongue (1796) included a “hog in armor” phrase similar to our modern meaning, but the lipstick variation is recent:
In 1985, the Washington Post quoted a San Francisco radio host on plans for renovating Candlestick Park (instead of building a new downtown stadium for the Giants): “That would be like putting lipstick on a pig.”
Ginger’s phrase of the day agrees.