Why are shore lighthouses often painted white?

Shore lighthouses are typically painted white to serve as a daymark, ensuring the structure stands out clearly against the prevailing background for mariners.1

While the primary function of a lighthouse is to provide navigation assistance through light signals at night, the structure's appearance during the day is also critical. By painting shore lighthouses white, they achieve the necessary contrast to be easily identified by those at sea. In contrast, lighthouses located in the open sea or those situated against a naturally light-colored background are often painted with conspicuous bands of contrasting colors, such as red or black, to ensure they remain visible and distinct.12