The upper band on Monaco’s national flag is red.
Monaco’s flag is a simple horizontal bicolour: red on top and white below. The two bands are equal in height, and the design contains no coat of arms or other central emblem. Its proportions are unusually compact at 4:5.
The colors are the heraldic colors of the House of Grimaldi, Monaco’s ruling dynasty, and have been associated with the family since at least 1339. The present plain bicolour was formally adopted under Prince Charles III on 4 April 1881.
Monaco’s flag is frequently confused with Indonesia’s because both use red above white. The key distinction is proportion: Monaco’s flag is 4:5, while Indonesia’s is 2:3. Poland reverses the arrangement, placing white above red. Monaco also has a separate banner of arms featuring red diamonds on white.