# Flag of Thailand

The flag of Thailand (Thai: ธงไตรรงค์; RTGS: thong trai rong, meaning 'tricolour flag') shows five horizontal stripes in the colours 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 colours are said to stand for nation-religion-king, an unofficial motto of Thailand, red for the land and people, white for religions and blue for the monarchy, the last having been the auspicious colour of Rama VI. As the king declared war on Germany that July, some note the flag now bore the same colours as those of the UK, France, Russia and the United States.

## Design

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".

### Colour standards

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.
| Colour | Colour | CIELAB D65 | CIELAB D65 | CIELAB D65 | CIELAB D65 | Other colour values | Other colour values | Other colour values |
| Colour | Colour | L* | a* | b* | ΔE* | RGB | HEX | CMYK |
| | Red | 36.4 | 55.47 | 25.42 | ≤1.5 | 165-25-49 | #A51931 | C24-M100-Y83-K18 |
| | White | 96.61 | -0.15 | -1.48 | ≤1.5 | 244-245-248 | #F4F5F8 | C3-M2-Y1-K0 |
| | Blue | 18.63 | 7.89 | -19.45 | ≤1.5 | 45-42-74 | #2D2A4A | C87-M85-Y42-K43 |

### Construction Sheet

* flag construction sheet

## History

The first flag used for Siam was probably a plain red one, first used under Narai (1656–1688). Naval flags later used different symbols on the red ground—a white chakra, or the Hindu mythological elephant Airavata inside the chakra.
Officially the first flag was created in 1855 by Mongkut (Rama IV), showing a white elephant on red ground, as the plain coloured flag was not distinct enough for international relations.
In 1916 the flag was changed to show a white elephant in royal regalia. In 1916, the current design, but with the middle colour being the same red as the outer stripe, was defined as the civil ensign. According to a popular legend, king Vajiravudh (Rama VI) was appalled when he saw the elephant flag flown upside down by one of his subjects by accident, which caused him to order the creation of a vertically symmetrical design. Initially (1916/17), this was a purely red and white design of five horizontal stripes. Later in 1917, the middle colour was changed to dark blue, which was similar in tone to indigo or purple, which at the time was regarded as the auspicious colour for Saturday, the day Vajiravudh was born. According to other sources, the blue was also chosen to show solidarity with the Allies of World War I, which also had the colours blue-red-white in their flags.

### Timeline

| Date | Use | Description |
| c. 1680 – c. 1782 | National ensign during late Ayutthaya and Thonburi periods | A red plain rectangular flag. |
| c. 1782–1855 | Civil ensign prior to 1855 | A red plain rectangular flag. |
| c. 1782 – c. 1817 | State and naval ensign decreed by Phutthayotfa Chulalok (Rama I) | Red flag with a white chakra, presumably to represent the Chakri dynasty. |
| c. 1817–1855 | Change instituted by Phutthaloetla Naphalai (Rama II) | Red flag with a white elephant inside the chakra. |
| c. 1843–1855 | Alternative civil ensign from 1843 to 1855 | A white elephant, facing the hoist, centred on a red field. Thai: ธงช้างเผือก (Thong Chang Puak) |
| 1855–1893 | National ensign decreed by Mongkut (Rama IV) | A white elephant, facing the hoist, centred on a red field. Thai: ธงช้างเผือก (Thong Chang Puak) |
| 1893–1916 | Civil ensign until 1916 | A white elephant, facing the hoist, centred on a red field. Thai: ธงช้างเผือก (Thong Chang Puak) |
| 1893–1898 | State and naval ensign, to be displayed defaced with the flyer's emblem on the upper hoist corner | A white elephant in regalia, facing the hoist, centred on a red field |
| 1898–1912 | State and naval ensign | A white elephant in regalia, facing the hoist, centred on a red field |
| 1912–1917 | State flag and ensign, decreed by Vajiravudh (Rama VI) | A white elephant in regalia, facing the hoist, centred on a red field |
| 1916–1917 | Civil ensign | Red flag with two horizontal white stripes one-sixth wide, one-sixth from the top and bottom |
| 1917–present | National flag, civil and state ensign | Flag with horizontal blue stripe one-third wide between white stripes one-sixth wide, between red stripes one-sixth wide, known as the Trairanga. |

## Maritime flags

The naval ensign of the Royal Thai Navy (RTN) is the national flag with a red circle in the middle that reaches as far as the red stripes at the top and bottom. In the circle stands a white elephant, in full caparison, facing the hoist. The kingdom's naval jack is the national flag defaced with the emblem of the Royal Thai Navy in the middle. The regimental colours of the RTN is as same as this flag; both ensigns were adopted in 1917.