What do the colours of the Slovakia flag mean?

White: pan-Slavic; also the double cross. Blue: pan-Slavic; also the three hills. Red: pan-Slavic; also the shield field.

How do you tell the Slovakia flag from the Slovenia one?

Slovenia's emblem is in the top hoist corner and shows a mountain and stars.

When was the Slovakia flag adopted?

The current design dates from 1992, and its official ratio is 2:3.

The flag of Slovakia

Three equal horizontal bands of white, blue and red, with a shield bearing a white double cross on three blue hills, set toward the hoist of centre.

Ratio 2:3 · current design adopted 1992

Slovakia flew the plain tricolour in the nineteenth century and added the shield in 1992, on independence, specifically because the plain version is the Russian flag. The shield is not centred: it sits slightly toward the hoist so it stays visible when the flag hangs slack. The double cross is one of the oldest continuously used Christian emblems in central Europe and appears in Hungarian heraldry too, reflecting the shared medieval kingdom. Slovenia solved the identical problem the same year with a differently placed emblem, which is why the two flags now resemble each other more than either resembles Russia.

Flags it gets confused with

Flag	How to tell them apart
Slovenia	Slovenia's emblem is in the top hoist corner and shows a mountain and stars.
Russia	Russia has no shield.

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
Double cross	The patriarchal cross of Saints Cyril and Methodius
Three hills	The Tatra, Fatra and Mátra mountain ranges

Ratio: 2:3
Current design adopted: 1992
Colours: white, blue, red

Common questions

What does the flag of Slovakia look like?: Three equal horizontal bands of white, blue and red, with a shield bearing a white double cross on three blue hills, set toward the hoist of centre.
What do the colours of the Slovakia flag mean?: White: pan-Slavic; also the double cross. Blue: pan-Slavic; also the three hills. Red: pan-Slavic; also the shield field.
How do you tell the Slovakia flag from the Slovenia one?: Slovenia's emblem is in the top hoist corner and shows a mountain and stars.
When was the Slovakia flag adopted?: The current design dates from 1992, and its official ratio is 2:3.

Slovakia Capital, area, population and currency
The flag of Slovenia Routinely mistaken for this one
The flag of Russia Routinely mistaken for this one
Every flag with white 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 Canada Ratio 1:2
The flag of Japan Ratio 2:3
The flag of France Ratio 2:3
The flag of Brazil Ratio 7:10
The flag of Italy Ratio 2:3

Sources

Wikidata — Wikimedia Foundation (CC0 1.0)

How these figures are compiled and checked