the paint code will be on
1) the vin plate, hidden within the vehicles code, there is probably something on google about how to read the vin plate on stilos, thus producing your paint code for you
2) on a sticker (silver on older fiats) in a door jam, or boot jam.
3) in the log book for when the car was delivered, it should have the receipt of delivery somewhere (unless its somehow got lost in its short life!!), which will tell you what options and spec it is, aswell as the paint and interior codes