There is some controversy over the meaning of the colors of the France flag as conditions and people’s opinions have changed over the years.

During the French Revolution, the Paris militia wore a cockade (a symbol usually worn on a hat) which was blue and red. These were the colors of Paris. Then white was added to it to form a tricolor cockade for the whole nation. Over time, these colors came to symbolize liberty, equality, and fraternity, the motto for the country and ideals of the French revolution.
There are many theories pertaining to the significance of the colors.
The flag of France is referred to as Tricolore, the French Tricolor, or simply, Tricolor. It was used during the French Revolution and has been the official flag since 1794 with one exception. Following Napoleon’s defeat at the battle of Waterloo, the Bourbon Dynasty was restored from 1814 to 1830.
After 1830, the tricolor was again the official flag after the Bourbons were overthrown.
The National Anthem of France is also known as the Marseillaise. Claude Joseph Rouget de Lisle wrote the words and composed the music and originally named it "Chant de guerre pour l'Armée du Rhin", translated "War Song for the Army of the Rhine." Because it was a strong and graphic song, urging people to fight and kill, it was banned by Napoleon and was adopted after 1879. It is called the Marseillaise because troops were singing it when they reached Marseillaise in 1792. It caught on and was sung in Paris by a battalion from Marseillaise, so the name stuck.
The motto of France is "Liberté, Equalité, Fraternité" or translated, "Liberty, Equality, Fraternity." It was one of many mottoes used during the French Revolution. When Germany occupied France during World War II, it was replaced by “Travail, famille, patrie" or "Work, family, fatherland." The Provisional Government of the French Republic (1944 to 1946) re-adopted the motto and it is included in both of the French constitutions of 1946 and 1958.
In ancient days, soldiers did not have uniforms, so a symbol was painted on their shields so they knew who was on their side, or who their enemy was.
When they were in the battlefield, they needed a way to see their leaders. So they attached to a pole an emblem, such as an animal, shield, or religious symbol. Some believe the Romans were the first to use a flag. They fastened a square piece of cloth to cross bars at the end of spears. Later, the idea of fastening a flag on the side of a pole was realized and this was the forerunner of the flag.