An interesting complement…
PATYA UCHMA – black pot, i.e. you are also well-versed in the Torah, as much as a pot is blackened from use (Rashi to Avodah Zarah 16b).
Or is the phrase an insult or simply a description of local customs of how the Rabbis dressed?
There are a number of references in the Talmud to the attire of Chazal. As above, on our daf, Rava refers to Rafram bar Papa as “you black pot.” In Pesachim (88.) Rav Nachman refers to Rav Eina Saba as “you black pot.” Again in Megillah (14:) Rav Nachman refers to Rav Eina Saba as a “black bowl”. The Maharsha suggests that Rav Nachman may have been alluding to Rav Eina Saba’s ugliness. Is it really possible that a Tanna would openly insult and disparage another Tanna? In Avodah Zarah (16:) Rav Assi refers to Rabbi Zeira as “you black pot.” Rashi (ibid.) suggests that he may have become grimy through toil (many Rabbis in Talmudic days were workmen) or that due to his preoccupation with his studies he had neglected the tidiness of his clothes. Again, it is difficult to accept that an Amora would openly insult and disparage another Amora. It is unlikely that Chazal wore dirty clothes, for the Gemara clearly teaches that a talmud chacham who wears soiled clothing is deserving of dire punishment (Brachot 43, Shabbat 114.).
Perhaps what is depicted here is a trend among Tannaim and Amoraim to wear dark colored attire. This may help to explain the tendency among modern-era Rabbonim to favor dark colored garments. Perhaps the Rabbinical attire is a uniform which helps the clergy to focus their attention on a higher calling. In fact, the Tanna Rabbi Yochanan referred to his special garments as “my honorers” (Shabbos 113:).
This clearly needs further elaboration but might help to explain what would otherwise appear to be a quite unpleasant nickname or insult.