The reason behind this color choice has to do with practicality. In the old times, Greek housewives would use a cleaning agent called loulaki (blue powder in English) which came in the form of talcum powder. It was widely and cheaply available across Greece.

The iconic blue-and-white aesthetic of Santorini is a blend of practical problem-solving, public health history, and national identity. Historically, residents used white limewash on their homes because it was an inexpensive and effective way to reflect the intense Mediterranean sun, keeping the interiors cool. In the late 1930s, the Greek government mandated the use of lime for its antibacterial properties during a cholera outbreak, solidifying the white look. The blue domes, primarily found on churches, represent the sky and the sea, which are central to Greek Orthodox symbolism and island life. In the 1960s and 70s, the military regime pushed this color scheme further to reflect the colors of the Greek flag and create a unified national brand for tourism. Today, while the "blue domes" are fewer in number than social media suggests, the combination has become the globally recognized symbol of the Cyclades, attracting millions who seek the stark contrast of white walls against the deep cerulean of the Aegean Sea.