Berets have been used by the Bundeswehr for many years now. Each color represents a different branch/position of the soldier, and we've got several to choose from.
Shell is 100% wool, liner is 100% cotton.
Here are the correlating branches with colors available:
Green = Panzer Grenadier, Jager and Wachtbattalion.
Light Red = Military Police (Feldjager), Artillery, and Combat Support Corps.
Blue = Medical Corps.
Navy Blue = Multinational Corps, Officer Cadet Battalions, Navy and Luftwaffe Security units.
NOTE: These are all used, which means they are all in useable shape, but don't expect them to be new. Some were tied tighter and sized smaller than what the tag reads. They can be stretched slightly, and I've sorted them based on their marked size unless the difference is drastic.