The National Flag of Greece consists of four white and five blue alternating horizontal stripes, with a white cross on the upper left corner. Blue and white are the national colours of Greece, as blue symbolizes the sky and seas and white denotes the purity of the Greek independence struggle.

The prominence of blue in Greece is deeply rooted in both the nation's geography and its revolutionary history. The specific "blue and white" color scheme was officially adopted in 1822 during the Greek War of Independence against the Ottoman Empire. According to popular tradition, the nine stripes on the Greek flag represent the nine syllables of the revolutionary motto "Eleftheria i Thanatos" (Freedom or Death), while the blue symbolizes the Aegean Sea and the white represents the purity of the struggle for independence. On a more practical level, the blue-and-white aesthetic of Greek island architecture—particularly in the Cyclades like Santorini and Mykonos—originally served a utilitarian purpose. In the late 19th and early 20th centuries, many homes were coated in white lime (asbestos-free) to reflect the intense Mediterranean sun and act as a natural disinfectant. The blue accents, often used for shutters and domes, were originally achieved using a cheap, widely available cleaning agent called "loulaki" (blue powder). In 2026, this color palette is strictly protected by local building codes to maintain the "national identity" and attract the millions of tourists who associate these colors with the quintessential Greek experience.