1999-2001 Jeep Cherokee and 1999-2004 Jeep Grand Cherokee uses this remote with FCC ID GQ43VT9T. There was a grey remote and a black remote. They were different colors to make it easy to tell driver 1s keys apart from driver 2s keys. There is no functionality that is different about grey and black remotes. It doesn't matter if you have one of each, three of one, or any other combination.
To make new remotes work with your vehicle, have a local automotive locksmith program the vehicle to accept new remotes.
Chrysler part numbers for this Jeep remote: 56036859AB, 56036859AD, 56036859AE, 56036860AD, 56036860AE