The national flag of the Netherlands (de Nederlandse vlag) is a horizontal tricolour of red, white, and blue. The current design originates as a variant of the late 16th century orange-white-blue Prinsenvlag ("Prince's Flag"), evolving in the early 17th century as the red-white-blue Statenvlag ("States Flag"), the naval flag of the States-General of the Dutch Republic, making the Dutch flag the oldest tricolour flag in continuous use. As a flag that symbolises the transformation from monarchy to republic, it has inspired both the derivative Russian flag, and after the French Revolution in 1789, the vertically striped French tricolour, both flags in turn influenced many other tricolours. During the economic crisis of the 1930s, the old Prince's Flag with the colour orange gained some popularity among some people. To end the confusion, the colours red, white and blue and its official status as the national flag of the Kingdom of the Netherlands were reaffirmed by royal decree on 19 February 1937. The national flag of the Netherlands is a tricolour flag. The horizontal fesses are bands of equal size in the colours from top to bottom, red (officially described as a "bright vermilion"), white (silver), and blue ("cobalt blue"). The flag proportions (width:length) are 2:3. The colour parameters were defined in November 1958 by the NEN (former HCNN) in as the following: In this definition, the colors are defined using CIE-1931 colour space and Standard illuminant C at a 45° angle. The Dutch flag is almost identical to that of Luxembourg, except that it is shorter and its red and blue stripes are a darker shade. The similarity of the two flags has given rise to a national debate to change the flag of Luxembourg, initiated by Michel Wolter in 2006. Each band of colour in the Dutch flag holds some symbolism for the country. The red band symbolizes bravery, strength, valor, and hardiness; the white band, peace and honesty; and the blue band represents vigilance, truth, loyalty, perseverance, and justice.