In military organizations, the practice of carrying colours, standards, flags, or guidons, both to act as a rallying point for troops and to mark the location of the commander, is thought to have originated in Ancient Egypt some 5,000 years ago. The Roman Empire also made battle standards, reading SPQR a part of their vast armies. It was formalized in the armies of Europe in the High Middle Ages, with standards being emblazoned with the commander's coat of arms.
General use
As armies became trained and adopted set formations, each regiment's ability to keep its formation was potentially critical to its, and therefore its army's, success. In the chaos of battle, due to the amount of dust and smoke on a battlefield, soldiers needed to be able to determine where their regiment was.
Regimental flags are generally awarded to a regiment by a head of state during a ceremony. They were therefore treated with respect as they represented the honour and traditions of the regiment. Colours may be inscribed with the names of battles or other symbols representing former achievements (see battle honours).
Regiments tended to adopt "colour guards", composed of experienced or élite soldiers, to protect their colours. As a result, the capture of an enemy's standard was considered as a great feat of arms.
They are never capriciously destroyed – when too old to use they are replaced and then laid up in museums, religious buildings and other places of significance to their regiment. However, in most modern armies, standing orders now call for the colours to be intentionally destroyed if they are ever in jeopardy of being captured by the enemy.
Due to the advent of modern weapons, and subsequent changes in tactics, colours are no longer carried into battle, but continue to be used at events of formal character.
Colours
Asia
Cambodia
In Cambodia, the Colours of the Military and other uniformed institutions follow British, US, and French practice. It is basically a large version of the Cambodian flag with the unit name below in white in the bottom blue stripe.
China, People's Republic of (Mainland China)
The People's Liberation Army is the overall body for the entire armed forces of the People's Republic of China, and is represented by a single flag, which serves as a ceremonial colour for all regiments and larger formations. This is based on the national flag, but has instead of the four smaller gold stars the Chinese characters for the numerals '8' and '1', which stands for the 1 August, which was the date in 1927 that the PLA was founded. When paraded, the flag is fringed with gold, and is mounted on a red and gold pole. However, each branch of the PLA has its own flag, based on the Army Flag, but are not taken out on public parades except with the same gold fringe as the latter: Ground forces: This is the Army Flag with the lower 40% coloured green. Navy: This is the Army flag except that the lower 40% has three blue and two white horizontal stripes of equal width. Air Force: This is the Army Flag with the lower 40% coloured air force blue. Rocket Forces: This is the Army Flag with the lower 40% being a gold stripe. Banners of the PLA
Individual unit colours based on the PLA service colour would only come in a test basis beginning 2018, when mobile contingents of units of the Northern Theater Command who took part in the joint military exercise "Vostok 2018" with the Russian Armed Forces carried red colours with the unit name on the white fringe nearest the flagpole. Test battle colours were formerly given out to the People's Armed Police in recent years before the practice was adopted by the PLA Ground Forces on an experimental period. During the 1 October 2019 civil military parade marking the 70th anniversary of the People's Republic of China, a mobile colour guard unit debuted after many years the garrison colours awarded to every PLA formation and agency, which are red with the formation or agency name in Mandarin Chinese in white or gold lettering (but without the white fringe), with some colours bearing additional inscriptions bearing either battle honours or decorations awarded to the formation or agency concerned.
China, Republic of (Taiwan)