The Flag of Mexico is a vertical Tricolour of green, white, and red with the national coat of arms charged in the center of the white stripe. While the meaning of the colors has changed over time, these three colors were adopted by Mexico following independence from Spain during the country's War of Independence. The current flag was adopted in 1968, but the overall design has been used since 1821, when the First National Flag was created. The current law of national symbols, Law on the National Arms, Flag, and Anthem, that governs the use of the national flag has been in place since 1984.
The official design of the Mexican Flag can be found in Article 3 of the Law on the National Arms, Flag, and Anthem, passed in 1984. While the exact shades of the flag have not been defined by law, the Interior Ministry, (Secretaría de Gobernación) has suggested the following tones in the Pantone system. The article dictates what must be featured on the flag and also its proportions. Copies of the national flag which are made according to this law are kept in two locations: the General National Archive (Archivo General de la Nación) and the National Museum of History (Museo Nacional de Historia).
"Art. 3: The Bandera Nacional is a rectangle divided into three vertical stripes of identical measures, with the colors placed in the following order from hoist to fly: green, white, and red. Centered in the white stripe, the National Coat of Arms has a diameter of three-fourths the width of the white stripe. The proportion of the flag is four to seven (Ratio 4:7). It could carry a rope or tie of the same colors below the truck".