What do the colours of the Morocco flag mean?

Red: the Alaouite dynasty, and the sharifs of Mecca. Green: the star; the colour of Islam and of hope.

How do you tell the Morocco flag from the Vietnam one?

Vietnam's star is solid yellow with five plain points; Morocco's is an interlaced green outline.

When was the Morocco flag adopted?

The current design dates from 1915, and its official ratio is 2:3.

The flag of Morocco

A red field with a green interlaced five-pointed star outlined at the centre.

Ratio 2:3 · current design adopted 1915

The star is drawn as a single interlaced line — a pentagram, not a solid five-pointed star — and it was added in 1915 by Sultan Yusef specifically so Moroccan ships could be told apart from other plain red Arab ensigns at sea. Red had been the Moroccan flag colour for centuries before that. Vietnam's flag is the same red field with a solid yellow star, which is the pairing worth knowing. The green outline is drawn without a fill, which most reproductions get right and some do not.

Flags it gets confused with

Flag	How to tell them apart
Vietnam	Vietnam's star is solid yellow with five plain points; Morocco's is an interlaced green outline.

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
Interlaced pentagram	The Seal of Solomon; the five points are the five pillars of Islam

Ratio: 2:3
Current design adopted: 1915
Colours: red, green

Common questions

What does the flag of Morocco look like?: A red field with a green interlaced five-pointed star outlined at the centre.
What do the colours of the Morocco flag mean?: Red: the Alaouite dynasty, and the sharifs of Mecca. Green: the star; the colour of Islam and of hope.
How do you tell the Morocco flag from the Vietnam one?: Vietnam's star is solid yellow with five plain points; Morocco's is an interlaced green outline.
When was the Morocco flag adopted?: The current design dates from 1915, and its official ratio is 2:3.

Morocco Capital, area, population and currency
The flag of Vietnam 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