The national flag of Peru, officially named the Bandera Nacional (Spanish for "National Flag") and often referred to as The Bicolour (la Bicolor), is a vertical triband with red outer bands and a single white middle band, as defined by Article 49 of the Constitution of the Republic of Peru. The current flag was adopted by the Congress of Peru on 25 February 1825, and modified in 1950. The symbolism of the flag's colors is uncertain, but according to Peruvian author Abraham Valdelomar, San Martín, having arrived on the coast of southern Pisco, was inspired by the colors of parihuanas, red-and-white flamingos. The flag proved difficult to adopt due to its complex construction; without standardized measurements in place at the time, a triangular flag proved difficult to build. === Flag of 1884 === After the War of the Pacific, the coat of arms in the flag was slightly altered to represent the territory lost after the Treaty of Ancón.