What do the colours of the Andorra flag mean?

Blue: taken from France, one of the two co-princes. Yellow: shared between the French and Spanish influences. Red: taken from Catalonia and Spain.

How do you tell the Andorra flag from the Romania one?

Romania has no coat of arms and equal bands.

When was the Andorra flag adopted?

The current design dates from 1971, and its official ratio is 7:10.

The flag of Andorra

Three vertical bands of blue, yellow and red, the yellow slightly wider, with a quartered coat of arms at the centre.

Ratio 7:10 · current design adopted 1971

The flag is a diplomatic sentence: French colours and Catalan colours combined, with arms quartering the emblems of the two co-princes who have jointly ruled Andorra since 1278. The blue is noticeably darker than either Romania's or Chad's and the yellow band is fractionally wider than the others. Without the arms the flag would be almost indistinguishable from Romania's, which is why the civil version is rarely seen. The 7:10 ratio is unusual in Europe and makes it look squarer than its neighbours' flags.

Flags it gets confused with

Flag	How to tell them apart
Romania	Romania has no coat of arms and equal bands.
Moldova	Moldova's arms are an eagle with an aurochs shield; Andorra's are quartered with a mitre.

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
Mitre and crozier	The Bishop of Urgell, one of Andorra's two co-princes
Three vertical bars	The Count of Foix, whose title passed to the French head of state
Motto VIRTUS UNITA FORTIOR	"Strength united is stronger"

Ratio: 7:10
Current design adopted: 1971
Colours: blue, yellow, red

Common questions

What does the flag of Andorra look like?: Three vertical bands of blue, yellow and red, the yellow slightly wider, with a quartered coat of arms at the centre.
What do the colours of the Andorra flag mean?: Blue: taken from France, one of the two co-princes. Yellow: shared between the French and Spanish influences. Red: taken from Catalonia and Spain.
How do you tell the Andorra flag from the Romania one?: Romania has no coat of arms and equal bands.
When was the Andorra flag adopted?: The current design dates from 1971, and its official ratio is 7:10.

Andorra Capital, area, population and currency
The flag of Romania Routinely mistaken for this one
The flag of Moldova Routinely mistaken for this one
Every flag with blue in it
The flag of United States Ratio 10:19
The flag of India Ratio 2:3
The flag of United Kingdom Ratio 1:2
The flag of France Ratio 2:3
The flag of Russia Ratio 2:3
The flag of Brazil Ratio 7:10
The flag of Australia Ratio 1:2
The flag of South Korea Ratio 2:3

Sources

Wikidata — Wikimedia Foundation (CC0 1.0)

How these figures are compiled and checked