Blue and white on the Greek flag represent the sky and the sea. The sea is critical to Greek livelihood. Much of Greece's industry is related to the sea, hence the importance of the color blue to the Greeks. Scholars also believe that the blue and white of the Greek flag may also be associated with Greek gods or goddesses.
The blue and white stripes of the Greek flag represent the nine syllables of the Greek phrase "Eleftheria i thanatos," which means "freedom or death," as well as the letters of the Greek word "eleftheria," which means "freedom." "Freedom or death" was the motto of the patriot revolution against Ottoman occupation in the early 1800s. Scholars also theorize that the nine stripes might be related to the nine muses. This has never been definitely established, however.
The blue and white cross represents the Greek Orthodox religion. Formerly, the national flag of Greece was simply a blue and white cross. The flag in its current incarnation has been used symbolically since 1828, but it did not become the national flag of Greece until December 22, 1978.
Although the colors of Greece's flag have been blue and white since 1822, the shade of blue has never been fixed.