All I know about court dress in Germany is that I've seen a lawyer who had not yet put his gown on in the Landgericht (higher court of first instance) treated as if he were not there, which reminded me of the English custom where the judge says in reply to the improperly dressed lawyer, 'I can't hear you, Mr X'. There aren't any robing rooms in German courts as far as I know.
Udo's law blog today comments on the Mannesmann trial that the lawyers should traditionally be wearing white ties, but they aren't. Here's an English summary:
bq. Traditionally, a white tie is worn by defence counsel in the courtroom. (Photo of Sven Thomas, Klaus Esser's lawyer, wearing a yellow tie). A journalist who was in the courtroom confirmed to me that the other lawyers almost without exception are wearing coloured ties. I usually wear a white tie on the first day of the trial if I don't know how tolerant the court is. Afterwards I wear a coloured tie if I have the feeling that there are any objections - because if there are, it would not be in my client's interest.
In the comments, there is one by Udo Steger, who reports on his experience as a trainee:
bq. Basic rule: the older the judge(s), the more formal the dress. The higher the court, the more formal the dress.
Amtsgericht (local court): usually doesn't matter unless it is a pullover and jeans; older judges prefer to see a gown. No trainers.
Landgericht (regional court): dark suit, white/blue shirt, discreet tie, almost all judges insist on the gown. Shoes with leather soles.
Oberlandesgericht (higher regional court and above): Black suit, white shirt, white tie, black shoes with leather sole
Arbeitsgericht (labour court, like industrial tribunal): Slightly, but only slightly, better dressed than the union secretary.
Udo Vetter adds a few details:
bq. The white tie is/was only in criminal matters, Landgericht and above, and at higher courts (Oberlandesgericht, Bundesgerichtshof/Federal Court of Justice).
In civil matters, to say nothing of the Arbeitsgericht, no-one takes any notice.
Gown is mandatory everywhere except at the Amtsgericht.
White tie is OK, but outside court you feel as if you were in fancy dress.
In England, barristers carry their stuff around in a cloth bag with a tin for the wig. You might see them walking from the Law Courts in London to their chambers in court dress, but they will normally remove the party gear before leaving court.
I expect Adrian will tell me how far barristers are obliged to wear black suits, or often black jackets with pinstriped trousers (if male).
Earlier entries about court dress in Germany and England.