For that matter, black clothing was considered a sign of mourning or being on trial and white clothing was a sign of joy. Thus, Jews wore white on Shabbat and even on Rosh HaShana in order to show confidence in Hashem’s mercy. In fact, the Arizal is quoted in Shaar HaKavenot as making a frightening statement about wearing black on Shabbat. Ashkenazi poskim point out that the talmidei chachamim of Pumpedita wore black clokes on Shabbat (Shabbat 147a). The Ben Ish Hai, on the other hand, paskens not to (Halachot Shana Shenia Parashat Lech Lecha Halacha 18). However, Rav Ovadia (lesheetato not to pasken according to Kabbala) says that the minhag of all gedolei hador today is to wear black suits and someone who wears white is acting incorrectly and should be instructed not to change from the minahg of the gedolim (Yalkut Yosef 262:2 in the name of Halichot Olam Part 4).
Thus we see that what is considered proper clothing can change from time to time and place to place although a talmid chacham should not wear either very cheap or very expensive clothing but nice, moderate, clean clothing (Rambam Hilchot Deot 5:9).