- colour: natural 100% natural cow leather, goat skin lining, rubber sole OPERA shoes are elegant and classic. Stylish sole on a small heel is lightweight and flexible. *When choosing shoes keep in mind the softness of the leather used. If your foot length is between sizes we highly recommend to choose a smaller size. The leather stretches adjusting the shoes to your feet. *Please note that leather is a diversified material, therefore each piece is unique. This leather changes over time, from year to year it darkens and gains nobility.