Canada.

There are only two colors in the flag.
And there are two graphic elements. A vertical tricolor plus the national symbol, the maple leaf.

The colors red and white are linked to Canadas historic ties to the two countries England and France.
In 1921, when Canada was a British dominion, King George the fifth proclaimed red and white to be the official colors of Canada. This has been upheld even though Canada became fully independent in 1931.

The red color came from Saint George’s Cross, the national flag of England.

The white color was regarded as the colors of the French, historically linked to the royal Bourbon dynasty.

Canada was a British colony from 1763 to 1867. The country was divided into several provinces and territories under British rule until it achieved confederation and self government in 1867. Canada remained a British dominion until 1931, when it became fully independent. As a result the flag used in Canada prior to the mid 1960s was very much associated with Great Britain, having the Union Jack placed in the canton of the Red Ensign flag.
The new flag design emerging in the 1960s was the result of a heated flag debate in Canada in the mid 1960s. Many believed that there was no reason to change what was the Canadian flag at the time, the Red Ensign with Union Jack in the canton.
Thousands of designs were considered, before the tricolor with a single maple leaf was eventually chosen by the flag committee of the Canadian parliament.

The maple leaf has been used as a prominent Canadian emblem since the 18th century.
It was first used as a national symbol in 1868 when it appeared on the coat of arms of both Ontario and Quebec. The maple leaf also had a prominent presence in song, literature, emblems and coins. During the First and Second World Wars, badges of the Canadian forces were often based on a maple leaf design. The maple leaf would eventually adorn the tombstones of Canadian military graves. For many, the maple leaf was a shared symbol of pride, courage and loyalty.

Three things worth noting about the Canadian flag.
Lester B. Pearson, prime minister in Canada from 1963 to 1968, was the one that made it his big political project to get Canada a new flag that was distinctive for the nation and something that defined Canada as a unified, independent country.
This was very controversial at the time, as many believed there was no reason to abandon The Red Ensignflag. This flag featured the Union Jack, a prominent symbol associated with Great Britain, in the upper left canton.
One reason why Pearson believed it was crucial to get a more distinctive flag for Canada, that was not so tied to the British, was linked to the dramatic events that unfolded in Egypt in 1956.
Conflict over the rights to the important waterway of the Suez canal led to a military conflict between Egypt and a coalition of forces from Great Britain, France and Israel.
Pearson, then minister of foreign affairs, acted as a broker in the conflict, something that also led to him being awarded the Nobel Peace Prize in 1957. One thing he witnessed with his own eyes, was how Canadian United Nations peace keeping units was mistaken for being British military forces. This was because of the Union Jack on the emblem of the Red Ensign Canadian flag.
If it had been up to Pearson himself, the new Canadian flag would have been a tricolor with blue bands instead of red. And three maple leafs would be in the middle instead of only one. This flagdesign is often referred to as the “Pearson Pennant”.

George Stanley, Dean of Arts at the Royal Military College in Canada, is the one that designed the Canadian flag.
His design bears a striking similarity to the flag of his employer, The Royal Military College. Both flags featured a vertical tricolor with a white middle band being flanked by two red bands. The only difference being the crest of the military school being replaced by a single maple leaf.
It’s worth noting that there was one minor change to Stanley’s design. Stanley’s maple leaf featured 13 points, while the final version incorporated only eleven.

On February fifteenth in 1965 the new flag was inaugurated in a public ceremony on Parliament Hill in the capital of Ottawa. Thousands of Canadians gathered as the Canadian Red Ensign was lowered and, at the stroke of noon, the new National Flag of Canada was hoisted.