Yes, German poodle clubs recognized by VDH all register partis and allow them at shows. Instead of two color groups we have three color groups. Poodles are judged within their size and color group for BOB (we call it BOB even though it should be BOVandColor):
- Black, white, brown
- Silver, fawn
- Harlekin (back and white parti), black and tan
Partis can get BOBs and their champion titles. At national shows, the partis with BOB go on to compete in the group ring. At international shows in Germany, they can get a BOB and CACs towards their German championship, but are not allowed in the group ring.
Depending on the specific club rules, solid dogs from parti parents can not show or breed.
If you have a solid poodle registered with a VDH poodle club, it says "(FCI)" after their name on the pedigree. It's easy to do a foreign registration with AKC with those pedigrees.
If I'd want a parti (stud), I'd look into importing from Germany. With shows and a strict breeding program overseen by the clubs, these lines have improved a ton in the last decades.