National flag common for colours to be presented in bands of three. It is common for many flags to feature national symbols, such as coats of arms. National patterns are present in some flags. Variations in design within a national flag can be common in the flag's upper left quarter, or canton. The most popular colours in national flags are red, white, green, dark blue, yellow, light blue, and black. The occurrence of each colour in all the flags is listed in detail in the table below. The table shows that the colours light brown, dark brown and grey only occur in
Flag of Poland as the official shades of both colours expressed as coordinates in the CIE xyY (CIE 1931) colour space with the tolerated colour differences (ΔE) specified in the CIE 1976 ("L"*, "u"*, "v"*) colour space (CIELUV). The Constitution contains no mention of a national flag. Instead, the flag is defined by the Coat of Arms Act which specifies two variants of the national flag: the national flag of the Republic of Poland ("flaga państwowa Rzeczypospolitej Polskiej") and the national flag with coat of arms of the Republic of Poland ("flaga państwowa z godłem Rzeczypospolitej Polskiej"). Both flags are defined in Article