ALIBI was a B-list French pop star on the European reality show circuit when she caught the attention of HEI$T. It seems she was using the shows as a cover for a crime spree, and she was pretty successful at it too. HEI$T recruited her to be a sort of mascot for the operation, she acts as human relations for their clients, wining and dining them. Turns out when she's pulling a robbery with the team, she keeps most of the attention on herself as well... We've noticed her taking a more and more active role in their operations, and can only assume HEI$T is continuing to groom her into leadership role.
The purple hair is reflective of her celebrity origin, and is intended to cause people to keep all eyes on her during an operation.