Teutonic sound is a figment of an american trumpet players imagination. It is not possible to emulate with a piston trumpet - or most modern german rotary Bb instruments either. It is not dark or bright or anything in between.
Older rotary trumpets were built to have a very thick sonorous low register, a very clear midrange and a brilliant high register. The construction of the trumpet with the special short leadpipe, bell with a big crown and heavy bracing made the instruments respond differently. Crescendos were playable with great control. The sound was much more articulate (which had a lot to do with the player - not just the horn). The sound did not mask other instruments sound as greatly. There was more life in the overtones. The F trumpet had much more color than the Bb trumpet, security became the only consideration and many started playing C trumpets.
Modern piston trumpets pitched in C used in orchestra have a creamy sound from low to high with far less "character" than the older instruments. Crescendos were not as controlled in there delivery of energy. The tone being "thicker" masks other sounds in the same register (violin and viola for instance), those players cannot hear themselves as well. That is pure CRAP for ensemble playing. We can hear the problems at almost any concert: the brass is either a bit too present or not present enough. There is the power to overpower but the unique voice that does not bury others but still is "present" is simply not available.
The closest thing to teutonic these days is how the Vienna Philharmonic plays followed by the Gewandhaus orchestra sometimes. If you want a good example of teutonic, listen to this frenchman who is actually a horn player, play this rotary Bb from around 1900:
J. N. Hummel 1/2 Trumpet concerto in E-flat major (David Guerrier, Nantes, 2005) - YouTube
J. N. Hummel 2/2 Trumpet concerto in E-flat major (David Guerrier, Nantes, 2005) - YouTube
I wish that more orchestras would spend more time on balance and color. I wish that the terrible development that makes modern instruments so "loud" and inflexible would be challenged. I wish that more players would discover "abandon" and "passion" instead of security by using the smallest instrument that we can get away with. No more piccs in Bolero, Tchaikowsky 4 or Symphonic dances from West Side Story, rotary F trumpets for Mahler and Brückner, natural trumpets for Beethoven and Mozart. There is a lot to discover. Talk is cheap.