Musar על שבת 237:3

Therefore the early sages occupied themselves in the preparation of the Sabbath, each sage according to his own way: "Rabbi Abahu used to sit on an ivory stool and fan the fire. Rav Safra would roast the head of an animal. Raba salted fish. Rav Huna would light the lamp. Rav Papa plaited the wicks. Rav Chisda cut beets. Rabbah and Rav Joseph chopped wood. Rav Nachman bar Isaac carried things in and out, saying: 'If Rav Ammi and Rav Assi visited me, would I not carry thus for them?'" (Shabbat 119a).

Let us return to the matter of [honoring] the Sabbath. Our sages said: "Rav Anan wore [black] overalls" (Shabbat 119a), i.e. he would wear a black garment on Friday so that the honor of the Sabbath would be more recognizable when he donned fine [Shabbat] clothing.