Kaeya is a tall and muscular man. He has a tanned complexion and navy-blue hair with streaks of lighter blue, accompanied by a waist-length lock of hair that begins at the base of his scalp on the back of his head at the left. His visible eye is periwinkle with a diamond-shaped pupil that is shared with other characters known to be from Khaenri'ah. Over his right eye, he wears a gold-trimmed black eyepatch that is mostly covered by his bangs.