A bit longer history:
The first inhabitant of Chad whose remained have been preserved is Abel, discovered in January 1995by the French paleontologist Michel Brunet. Abel even predates the famous Lucy, found in Ethiopia.Lucy's "father" Yves Coppens admitted that the centre of early appearance of modern humans must nowbe considered to be Chad. Rock paintings and engravings found in the Tibesti and the Ennedi demonstratea more recent but still very ancient populating of the area. Chad has been for centuries a contact zonebetween the Arabs from Northern Africa and the inhabitants of subSaharan Africa. Therefore, the history ofChad is characterized by ethnical and religious disputes which are not solved yet. Chad was not only acrossroad of transSaharan commercial trails, but had also its own wealth, mainly salt and copper mines.

The oldest known kingdom in Chad was found in Kanem by the Sefawad dynasty in the XIth century. Around 1100,the rulers ("mai") were converted to Islam, which spread all over the area. The kingdom had a big army, apowerful administration and a flourishing economy. However, internecine quarrels and religious dissenssionsundermined the Sefawad power. The Boulala, vassals of Kenam, revolted. In the XIVth century, the Sefawadfled from Kanem because of repeated attacks by Arab tribes. The Sefawad restored their power in Bornou,west of lake Chad, in the XVth century. Mai Idris (1497-1519) invaded Kanem and incorporated it to hiskingdom, which stretched from Kano (now in Nigeria) to Darfour. Other kingdoms were founded in the area,namely Ouaddai (XIVth century) and Baghirmi (XVIth century), which were vassals of Kanem-Bornou. The main resourceof this kingdom was slave trade with Arabia, which motivated conquest wars.

In the middle of the XIXth century, the Fulani ruler Ousman dan Fodio founded the Caliphate of Sokoto (now in Nigeria)and called for jihad. Fodio attacked the kingdom of Kanem-bornou but was repelled by Prime Minister Muhamad Amin al-Kanemi.The Prime Minister modernized the monarchy and confiscated the power, which he transmitted to his son Umar.He built a new capital city, Kouka (now in Niger). During the troubles, Ouaddai regained its autonomy andannexated Baghirmi. At the same time, the Sinussi confrery became very popular in the area. In 1860, all theserival kingdoms had fallen into decline. In 1879, Rabah, a slave merchant from Sudan, conquered Ouaddai. He ruledover the east of Chad and maintained an army of 35,000. Commerce of ivory and slaves allowed him to buy modernguns and ammunition and to found a vast empire.

In the middle of XIXth century, European explorers such as Heinrich Barth, Clapperton and Nachtigal visited centralSudan. In 1891, Monteil reached lake Chad from Senegal. France then decided to conquer Chad in order to connectits other possessions in Africa. On the pretext that Rabah was an esclvagist, France sent three missions fromAlgeria, Niger and Congo in order to get rid of him. The three missions joined near the lake Chad in 1899, andRabah was defeated and killed in Kousseri in 1900. Rabah's empire disappeared but the Senussi resisted theFrench "pacification" until 1917. In 1900, a Decree created the "Territoire militaire des pays et protectoratsdu Tchad" (Military Territory of the Chad Countries and Protectorates"), which was integrated to the Oubangui-Charicolony (now the Central African Republic). In 1920, Chad became an autonomous colony ruled by a civil administration.In 1923, the border with Sudan was fixed. Six years later, the Tibesti was incorporated to Chad. In 1936, an agreementbetween France and Italy planned the cession of the Aozou stripe, in the north of the country, to the neighbouringItalian Libya. The agreement, however, never came into effect. France hardly developed the Chad colony. Cultivationof cotton was imposed in the south and several Chadians were forced to work for the building of the Congo-Oceanrailway, which caused several revolts.

During the Second World War, the Governor of Chad was F�lix Ebou� (1884-1944), former Governor of Guadeloupe (1936)and first black man to have been appointed colonial Governor. In August 1940, Ebou� decided to rally de Gaulle andChad was the first colony to join the Free France ("France Libre"). Chad was an important starting point for themilitary operations led by Leclerc in the Libyan desert (1941-1943).

After the war, Chad elected representatives to the (French) Constituant Assemblies (1945-1946) and to the NationalAssembly (1946). The fight for independence was started by Gabriel Lisette, the founder of the Chadian ProgressistParty in 1946, and F�lix Tombalbaye. Chad gained independence on 11 August 1960.

Tombalbaye forced Lisette to exile and established an authoritarian regime, which turned into a dictatorship oncethe Chadian Progressive Party had became the single party. The regime violently repressed the revolt of the northernMuslims in 1963. An armed insurrection bursted out in 1965 and the Chad National Liberation Front (Frolinat)was founded in 1966, leading a vast national rebellion movement. In spite of the French help and division amongthe rebels, Tombalbaye could not get rid of the insurrection. In 1972, he asked for Libyan support and promisedColonel Qaddafi to cede him the Aozou stripe as a reward. Qaddafi did not help the Chadian government but occupiedthe Aozou stripe, where uranium and manganese had been found. In 1973, Tombalbaye tried to tighten a few screwsby promoting the "chaditute".

Tombalbaye was killed during a coup in 1975 and General F�lix Malloum succeded him, increasing the dictatorship.The rebels launched a new campaign in 1977 and one of their leaders, Hissene Habre, was appointed Prime Ministerin 1978. However, the civil war got even stronger in 1979 and was internationalized because of the French militaryintervention and the Libyan mediation. A new national union government, presided by Goukouni Oueddei, Habre'shistorical rival, and supported by Libya, was set up in 1979. Libya intervened militarily in December 1980 andthe war between Habre's and Oueddei's factions resumed. In 1982, Habre seized N'Djamena and was appointed Presidentof the Republic. He was supported by France in his reconquest of the north of the country. France did not fightdirectly against Libya but ensured a military protection up to the 16th parallel. In 1987, the reconquest of thenorth of the country was achieved and the Libyan base of Maaten-es-Serra was destroyed.

In 1990, Idriss Deby, supported by Libya, overthrew Habre. A national reconciliation conference restored democracyand multipartism in 1993. The Aouzou stripe was definitively allocated to Chad in 1994 by the InternationalJustice Court. In 1996, a new Constitution was passed and Deby won the presidential election. He was reelected on May 2001.
Ivan Sache, 11 April 2003, based onHistory of Chad

The Constitution of 16 April 1962 stated the:
"The national emblem is the tricolour flag, blue, gold and red in vertical bands."
This flag was evidently inspired by the French Tricolore flag and the pan-African colours,which were altered (blue instead of green) to avoid confusion with flags of the neighbouring countries.
Official symbolics of the colours is:
- Blue: sky, hope, agriculture and the south of the country (waters);
- Yellow: sun, north of the country (desert);
- Red: progress, unity, sacrifice.

I rencently bought an issue of the Afrique contemporaine review. That issue includes the full text of the newest (14 April 1996) constitution of Chad.

Here are the flag and coat-of-arms related parts:

Chad adopted a new Constitution 2018, description of national symbols remained unchanged.
https://www.letchadanthropus-tribune.com/wp-content/uploads/2020/12/Constitution-du-Tchad-revise%CC%81e.pdf
The ratio is unspecified, and I haven�t found any color specification document.
 Zoltan Horvath, 2 May 2024

Color specifications

The French Navy flag book L'Album, 2000[pay00] gives this colour approximation for the Chad flag:
blue Pantone 281c - CMYK 100-70-0-35
yellow Pantone 116c - CMYK 0-10-95-0
red Pantone 186c - CMYK 0-90-80-5
This gives blue slightly darker then that given forRomania (both are approximationsmade by Armand du Payrat, the editor of the Album, based on flag reported in use).
Željko Heimer, 29 March 2003

The Flag Manual - Beijing 2008 gives Pantone colors: PMS 032 (red), PMS 109 (yellow), and PMS 293 (blue).

Flags and Anthems Manual London 2012 [loc12] gives Pantone colors: PMS 281 (blue), PMS 116 (yellow), and PMS 186 (red).

The Album des Pavillons 2023 already specifies the colors of the flags in three color systems.
Blue: Pantone 281c, CMYK 100-89-34-21, RGB 0-37-105
Red: Pantone 115c, CMYK 4-92-83-0, RGB 222-47-45
Yellow: Pantone 281c, CMYK 2-9-91-0, RGB 255-222-0

Vexilla Mundi gives colors in Pantone system: PMS Reflex blue, PMS 116C (yellow), and PMS 186C (red).

Wikipedia (English version) doesn�t give colour specifications, but theFrench version gives the color values as follows:
Blue: Hex: #002669, RGB 0-37-105, Pantone 281c, CMYK 100-64-0-59
Gold: Hex: #FFCC00, RGB 255-204-0, Pantone 116c, CMYK 0-20-100-0
Red: Hex: #D20F36, RGB 210-15-54, Pantone 186c, CMYK 0-93-74-18
The French version called the blue shade Indigo blue, and yellow is indicated as Gold.

Flag Color Codes gives the following color values:
Blue: Hex. # 002664, RGB 0-38-100, CMYK 100-78-0-57, Pantone 281, RAL 5026
Yellow: Hex. # FECB00, RGB 254-203-0, CMYK 0-10-98-0, Pantone 116, RAL 2007
Red: Hex. # C60C30, RGB 198-12-48, CMYK 0-100-80-5, Pantone 186, RAL 3028

Zoltan Horvath, 2 May 2024