William, from the excellent publication by Lancia to celebrate the Aprilia's 50th anniversary the colours are listed as follows:-
Model 238 (1st series) Grigio, Blu, Nero, Granada, Verde, also for Lusso model colours Metallic (although not stated what colours!)
Model 239 (Chassis) Blu Lancia, Grigio chiaro, Beige chiaro.
Model 438 (2nd series) Grigio metallic, Blu, Nero, Beige, Verde, Bruno chiaro, Metallic scuro, Bruno, Blu metallic, Grigio acciaio, Grigio chiaro, Nocciola, Beige, Amaranto.
Model 439 (2nd series chassis) grigio metallic, Blu.
There is also a full list of which interior colour matches the paint colour, but if I include all of these I will be here all night!!
Regards Ade.