It depends on your time in mourning. For the first year, black and heavy veils are mandatory. In the second, a deep blue. In the third through fifth year, purple, and jewelry is allowed, indicating a slighted mourning and return to the world.
[ Jaume answers, while Gaunt busies himself with his own clothes, not caring much about modesty. She can get a good view of just how scarred (and strong) his back is. ]