Thailand

The flag of Thailand consists of five horizontal stripes of red, white, blue, white and red, with the central blue stripe being twice as wide as each of the other four. The design was adopted on 28 September 1917, according to the royal decree issued by Rama VI. Since 2016, that day is a national day of importance in Thailand celebrating the flag.

The Flag Act of BE 2522 (1979) stipulates the design of the national flag as "rectangular in shape with 6 part width and 9 part length, divided into five stripes throughout the length of the flag; with the middle stripe being 2 part wide, of deep blue colour, and the white stripes being 1 part wide next to each side of the deep blue stripes, and the red stripes being 1 part wide next to each side of the white stripes. The National Flag shall also be called the Tri-Rong flag". The flag is almost identical to the Flag of Costa Rica because they both feature five horizontal stripes of red, white, and blue, with the center stripe being twice as thick as the others. However, the color orders are reversed. The colours of the flag were standardised in an announcement of the Office of the Prime Minister dated 30 September 2017, on the occasion of the 100th anniversary of its adoption. It gives recommended values for determining the standard colours of physical cloth flags, defined in the CIELAB colour space under Illuminant D65. RGB, HEX and CMYK values are derived by NSTDA.