Why are so many countries' flags red, white and blue?

Some of the countries with red/white/blue flags have inherited the colors from the British flag, directly or indirectly (Liberia). I am curious about Thailand as they have an Anglophile system of government. I am also curious about the origin of the Cuban flag and I wonder if it may be based on the US flag.

Arab countries seem to have a liking for Green / black / white and red, in that order. There’s probably some reason behind it.

Yep. The three primary colors for pigment (subtractive color system) is, as you noted Red, Blue, and Yellow. Mix them all together and you get Black.

The three primary colors for light (additive color system) are, Red, Green, and Blue. Mix them all together and you get White.

Cecil Sez…If blue, red, and yellow are primary colors, why do color TVs use blue, red, and green?

According to Flags of the World,

It’s also interesting to note that the Cuban flag is almost identical to the Puerto Rican flag, but with the blue/red reversed and the Cuban flag being longer.

According to this,

While this has been mentioned in a roundabout way, I’ll sum it up in my way.

It likely has alot to do with the fact that the UK had such a successful history of colonialsim and empirialism. Alot of formative countries were heavily influenced by the colors of the UK.

That may have something to do with it; I count 6 out 27 countries flying the red white and blue that were British or ex-British colonies (USA, Myanmar, Australia, New Zealand, Panama, and the UK itself). Still, most ex-British colonies did not pick British colors. Jamaica and Ghana both fly black, gold, green and red; the magnificent Kenyan flag is black, green, red and white; Barbados flies black, blue and gold; India flies blue, gold, green and white; and the Bahamas fly black, gold, and aquamarine, I kid you not.

The colors of the Union Jack itself come from the red Cross of St. George, patron saint of England, being combined with the white, X-shaped cross on a blue field of St. Andrew, patron saint of Scotland, and then further combined with the red, X-shaped cross of St. Patrick, patron saint of Ireland. How these saints came to be associated with these particular crosses and colors, I don’t know.

You mean the Puerto Rican flag is almost identical to the Cuban flag. The Puerto Rican flag was from 1895, more or less, and the Cuban flag was first.

Yea, the colors of the Cuban and Puerto Rican flag are reversed. The blue in the Puerto Rican flag represents the sky, and the star alone certainly does not represent another state of the USA.

Sites about the Puerto Rican (and Cuban) flag:

Welcome to Puerto Rico Note that this information is the one of the official government after it adopted the flag in 1952.

El Boricua The site of the name is in Spanish, but the information is in English

Puerto Rican flag What the writer(s?) says of identifying people by the hue of blue they have on their flag is mostly true.

Those are a few I found.

You’ve obviously not come across the unofficial, pre-Confederation flag of Newfoundland, the famous green-white-pink tricolour.