Munsell colour system - a system of colour notation devised by Albert Munsell which breaks colour into three attributes: (1) hue colour, red, blue, green etc; (2) value, the lightness or darkness of a colour; (3) chroma, strength or saturation of a colour
Specifications for the distinguishing sign of the Member State of registration to be affixed at the extreme left of the registration plate. Colours:
1. Retro-reflecting blue background (Munsell reference 5,9 pb 3,4/15,1) ...