When driving across Europe, you may find that highways do not have the same color in all countries. In Kosovo, Switzerland, Italy and Sweden they are green, while in Germany, France and Austria they are blue.
The reason is the international rules of communication, which allow both colors to be used.
The colors of highway navigation boards are arranged by the Vienna Convention on Road Signs and Signals, adopted in 1968 under the auspices of the United Nations.
The purpose of this convention is to harmonise road signals between states so that drivers can know the signs and understand their meaning, regardless of which country they are in.
The convention stipulates that highway navigational signs can have a green or blue background with white inscriptions. So countries have the right to choose one of these two colors, but they have to implement the system uniformly.
Which countries use blue boards, and what green ones?
Blue tables are used in Germany, France, Austria, Norway, Spain, and Portugal.
Meanwhile, green boards are used in Bosnia and Herzegovina, Croatia, Serbia, Switzerland, Italy, Sweden, Finland, Bulgaria and other countries.
Hence, differences in the colors of the signs do not imply that some states do not respect international standards. Rather, both options are in advance with the Vienna Convention. /Telegraphy/