What do the colours of the Bahrain flag mean?

Red: the traditional colour of the Gulf sheikhdoms. White: peace, and the truce treaties with Britain.

How do you tell the Bahrain flag from the Qatar one?

Qatar is maroon rather than red, has nine points, and is much longer at 11:28.

When was the Bahrain flag adopted?

The current design dates from 2002, and its official ratio is 3:5.

The flag of Bahrain

A red field with a white band at the hoist, separated by five white triangular points.

Ratio 3:5 · current design adopted 2002

Bahrain had eight points until 2002, when the number was reduced to five to match the pillars of Islam and to widen the gap with Qatar's nine. The white hoist band originates in the nineteenth-century truce treaties: Gulf states added white to their red flags to signal they had made peace with Britain. Bahrain's red is a bright scarlet against Qatar's maroon, and its 3:5 ratio is ordinary where Qatar's is extreme. The serration itself is what makes both flags unmistakable in a lineup.

Flags it gets confused with

Flag	How to tell them apart
Qatar	Qatar is maroon rather than red, has nine points, and is much longer at 11:28.

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
Five points	The five pillars of Islam

Ratio: 3:5
Current design adopted: 2002
Colours: red, white

Common questions

What does the flag of Bahrain look like?: A red field with a white band at the hoist, separated by five white triangular points.
What do the colours of the Bahrain flag mean?: Red: the traditional colour of the Gulf sheikhdoms. White: peace, and the truce treaties with Britain.
How do you tell the Bahrain flag from the Qatar one?: Qatar is maroon rather than red, has nine points, and is much longer at 11:28.
When was the Bahrain flag adopted?: The current design dates from 2002, and its official ratio is 3:5.

Bahrain Capital, area, population and currency
The flag of Qatar Routinely mistaken for this one
Every flag with red in it
The flag of United States Ratio 10:19
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

Sources

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

How these figures are compiled and checked