Both the civil and state flag of the German state of Saxony feature a bicolour of white over green, similar to the Austrian province of Styria although they are historically not related to each other.
The civil bicolour flag of white over green was used before World War II, and formally abolished in 1935, under the reforms of the Third Reich.
It was readopted 1945 when Saxony became a state again, and abolished 1952 under governing reforms of the German Democratic Republic.
When Germany was reunited, Saxony became a state again, and so the flag was finally officially readopted in 1991, having been a much used symbol during the demonstrations in the German Democratic Republic in 1989/90.
Paragraph 4 of Article 2 of the Constitution of the Free State of Saxony guarantees other flags equality alongside the Saxon state flag.