Hey, it's not cream, it's "primrose". According to Jon, Warwick #15 might have the only one in this hue.... Nearest modern equivalent seems to be a yello post-it note!
The Peerless was originally Bloo, same as Frank J's, actually called Corsican Blue. Nearest modern shade is Mazda Maxi Blue, or I can find you the exact mixing instructions for Automotive Paint in Newbury who will produce cellulose (tins or aerosols) to order.
Are you going to repaint it? It looks good in Bloo...
I have a copy of an origional sales flyer for The Warwick G.T. two Litre and in it says: The interior of the car is standard with black carpets and grey trim and the headlining is of washable plastic. The car can be supplied with Right or Left hand drive in a range of five standard colours - red, green, yellow, grey or blue.