National colours of Greece

[7] Blue and white appear to have been historically used by Greeks for several centuries, and were used during revolts against the Ottomans prior to the 1821 revolution.

[11] In addition to the constitution, the delegates selected Athens as the new national capital, though it had yet to be conquered from the Ottoman Empire.

[12] They also selected a new standard for the troops, a "white cross on an azure field",[12] a new naval flag, and new national colours, sky blue and white;[13][14][15] the new colours replaced those used by Alexander Ypsilantis, and the black used by the Filiki Eteria,[12][16] and were specified in the Constitution.

[17] The coat of arms of Greece consists of a white cross on a blue escutcheon which is surrounded by two laurel branches.

[22] An official report from the 1896 Summer Olympics stated that pigeons adorned with ribbons in the national colours were released from Panathenaic Stadium after Spyridon Louis, winner of the marathon, was introduced to accept his medal and a trophy.

The Flag of Greece since 1978, and the nation's naval ensign and co-national flag from 1822 to 1978, are in the national colours
An 1852 oil painting by Theodoros Vryzakis illustrating bishop Germanos III of Old Patras blessing the blue and white Greek banner at Agia Lavra at the outset of the national revolt against the Ottoman Empire on 25 March 1821.
The current coat of arms of Greece , in the national colours, was established on 7 June 1975