As noted elsewhere, some parking bays in the Wentworth car park are marked on the ground in blue. These are “medium stay”, ie up to 4 hours. A parking disc is required (and no return is permitted within 5 hours).
Others bays are marked on the ground in white. These are for all-day parking, which is free (no disc required).
So what colour - in a technical/legal sense - is this parking bay?