The cast-alloy wheels on the DeLorean car were designed specifically for DMC by Ital Design's Giorgetto Giugiaro.
Though they look similar, there are two different sizes, two different colors, two different castings and two different color center caps used throughout production.
Front wheels are 14" and rear wheels are 15" nominal diameter (tire spec).
Differences in colors and castings are illustrated below. Early cars, up to approximately VIN 1883, used a dark grey wheel with matching center cap and most likely a "deep" casting between the fins as shown below:
Later wheels, after 1883 were silver in color with a black (with silver DMC logo) center cap and either a "deep" or a "shallow" casting between the fins as shown in the photo below:
There is a period where there were deep-casting wheels painted the light silver, so overall there are three possible wheel "styles" in use.
It's rare, but not unheard of to have wheels all the same color but with different castings on the same car. This typically goes back to an owner damaging a wheel and the local dealer not having the correct replacement (or not being aware of the differences) on hand.
DMC sells refurbished wheels - we'll send you out wheels (individually or as a set) that are in the casting and color you specify and collect a core charge from you which is refunded upon return of your old wheels. If your wheels are bent or have severe "curb rash" or other damage, you may be best off sending us a photo of the damage to see if it is acceptable as a core. The only way to spot a bent wheel is to spin it on the car while watching the inside and then outside edges of the rim. A bent wheel will most likely be rejected as a core.