Liturgical Shoes and Stockings of Cardinal Sapieha

During a solemn liturgy, each bishop wears few additional vestments comparing with an ordinary priest.
Two of them are shoes and stockings (Buskins) in the liturgical color of the day.

The prayer recited by a bishop, while he puts on the buskins, explains symbolism of these vestments:

Calcea, Domine, pedes meos in praeparationem evangelii pacis, et protege me in velamento alarum tuarum.

Shod my feet, Lord, unto the preparation of the gospel of peace, and protect me under the cover of thy wings. (Ephesians 6, 15 and Psalm 60, 5).

Source LINK