The Greeks did manage to set up a lasting colony in
Ancona, more or less two thirds of the way up the Adriatic coast of Italy. The name of the city is straightforward Greek, it means "elbow", from the shape of the coast where the original town was founded.
Greek traders also were allowed to live in the Etruscan city of
Spina, near the mouth of the Po river and really close to the location of modern Venice, so the town's culture was heavity influenced by Greek civilization. Research referenced to in the linked Wiki article suggests that Spina's population might have been Hellenized.