What do the colours of the Malaysia flag mean?

Red: courage. White: purity. Blue: the unity of the Malaysian people. Yellow: the royal colour of the Malay rulers.

How do you tell the Malaysia flag from the United States one?

The US has thirteen stripes and fifty white stars; Malaysia has fourteen stripes and a yellow crescent and single star.

When was the Malaysia flag adopted?

The current design dates from 1963, and its official ratio is 1:2.

The flag of Malaysia

Fourteen alternating red and white horizontal stripes with a blue canton bearing a yellow crescent and a fourteen-pointed yellow star.

Ratio 1:2 · current design adopted 1963

The Jalur Gemilang has fourteen stripes and fourteen star points because Malaysia had fourteen states in 1963; when Singapore left in 1965 the count was kept and the fourteenth element reassigned to the federal territories. The stripe-and-canton layout is modelled on the United States flag, which the 1949 competition winner, Mohamed Hamzah, acknowledged. The result is that Malaysia is one of the flags most often mistaken for the American one in small reproductions. Yellow is specifically the colour of Malay royalty and appears for that reason.

Flags it gets confused with

Flag	How to tell them apart
United States	The US has thirteen stripes and fifty white stars; Malaysia has fourteen stripes and a yellow crescent and single star.
Liberia	Liberia has eleven stripes and one white star on blue.

What the colours mean

Flag laws usually specify a Pantone chip, a CMYK mix or just a colour name. Converting any of those to sRGB is lossy, which is why published hex values disagree.

The symbols on it

What	What it stands for
Fourteen stripes and fourteen star points	The thirteen states and the federal government
Crescent	Islam, the state religion

Ratio: 1:2
Current design adopted: 1963
Colours: red, white, blue, yellow

Common questions

What does the flag of Malaysia look like?: Fourteen alternating red and white horizontal stripes with a blue canton bearing a yellow crescent and a fourteen-pointed yellow star.
What do the colours of the Malaysia flag mean?: Red: courage. White: purity. Blue: the unity of the Malaysian people. Yellow: the royal colour of the Malay rulers.
How do you tell the Malaysia flag from the United States one?: The US has thirteen stripes and fifty white stars; Malaysia has fourteen stripes and a yellow crescent and single star.
When was the Malaysia flag adopted?: The current design dates from 1963, and its official ratio is 1:2.

Malaysia Capital, area, population and currency
The flag of United States Routinely mistaken for this one
Every flag with red in it
The flag of United Kingdom Ratio 1:2
The flag of Canada Ratio 1:2
The flag of France Ratio 2:3
The flag of China Ratio 2:3
The flag of Germany Ratio 3:5
The flag of Russia Ratio 2:3
The flag of Italy Ratio 2:3
The flag of Mexico Ratio 4:7

Sources

The World Factbook — Central Intelligence Agency (Public domain (US Government))

How these figures are compiled and checked