The "petit costume" was worn to and from the cathedral and the actual coronation "grand costume" over the top robe and dress. Napoleon was not a fashion hound. He generally found a look and stuck to it. It was often noted that he was the most shabbily dressed person in the room on many occasions. He was just a soldier at heart.
But. When there was an event, he really got involved. He knew that appearance was important to the Parisians, so he dressed to impress. One of the best pictures I found in a book was of these gloves and stockings. I assumed they were Josephine's, but to my surprise they were Napoleon's The stockings are silk and the gloves are white kid. The embroidery was done with gold thread. These items still exist in the Musee des Arts de la Mode in Paris, and I hope to see them on my next trip.