Institutional Apparel: Averted.  Pre-conviction, while the Empire will confine the accused, they don’t own the accused, who may, after all, be innocent as the day is long.  So they get to keep their own clothing and other perquisites until the trial is done.

(Post-conviction, since the Imperials don’t use prison as a punishment – it being horribly inhumane – the prisoner proceeds quickly enough to the cashier, the memetic reconditioner, the euthanatrist, or the executioner that Institutional Apparel would be unnecessary.)