According to Don's memories, he and his wife both died soon after Don aged into an adult. According to his SimDNA in SimPE, Nicolo's hair was black before it turned grey. According to his age data, he had 25 days left in the elderlife stage when he died. Like most pre-made deceased Sims from The Sims 2, Nicolo is completely unplayable without the use of hacks or third party programs, such as SimPE.
This Sim has no character data and cannot be resurrected in-game. For more information, read this guide.