The color of this bracelet is achieved naturally by treating it with heat, so avoid high heat that might alter it. As long as the sealant coat is intact it will not tarnish or change color, so clean it with ordinary hand soap and water if needed. Do not polish vigorously or use copper or brass cleaners; they are unnecessary and can damage and dull the sealer. Do not clean ultrasonically; it can loosen and damage the sealant coat. Avoid contact with solvents like nail polish, polish remover and petroleum products.
Your bracelet is wrist shaped--a flattened oval--but it may not be exactly your wrist shape. If you want to adjust the fit do it slowly and gently, with both hands wrapped around the bracelet to support it from all sides. Shape it a little at a time instead of in one big push that might crease it.