The national flag of the Principality of Andorra was adopted in 1866. The flag is a vertical tricolour of blue, yellow, and red with the coat of arms of Andorra in the centre. Although the three vertical bars may at first appear to be of equal width, the centre yellow bar is slightly wider than the other two so that the ratio of bar widths is 8:9:8. The overall flag ratio is 7:10.