In the prophet Zechariah's vision, what was Joshua the high priest wearing at first?

Answer: Filthy garments

Joshua stood in filthy garments; the angel had them removed, saying, "I have removed your iniquity," and clothed him in splendid robes.

“Now Joshua was dressed in filthy garments as he stood before the angel. So the angel said to those standing before him, “Take off his filthy clothes!” Then he said to Joshua, “See, I have removed your iniquity, and I will clothe you with splendid robes.””— Zechariah 3:3-4 (BSB)