blue light special

The phrase "blue light special" commonly refers to a promotional offer or a sale on specific products in a retail store, typically announced with a blue flashing light to grab the attention of shoppers. It originated from the practice of Kmart stores in the United States, where a blue light would be activated to mark a limited-time special deal or discount on certain items. This phrase has since become a colloquialism for any sudden or impromptu sale or discount in various retail contexts.