The origins of the term "lily white" in Ireland are unclear, but it is thought to have originated in the 19th century when the British government began to encourage the immigration of Protestant English and Scottish settlers to Ireland. These settlers were often referred to as "lily whites" because of their pale skin, which was seen as a sign of their purity and superiority over the native Irish population.
In modern Ireland, the term "lily white" is still sometimes used in a derogatory way, but it is also increasingly being reclaimed by people who are proud of their Irish heritage. For example, the term is often used by Irish sports fans to describe the national team, which is nicknamed the "Lilywhites".