1997 RAV4 RS3000 Remote

I recently bought a 1997 RAV4 and it has the RS3000 security system installed but came with no remotes. I bought a used grey remote off Ebay, and tried to program it, but no luck. I'm told that this remote should be black for 1997 and grey is for 1998, is it just a color change or is there really a difference?

I tried to program the remote using the process in the owners manual (turn key to ON, hold button on ECU until monitor light comes on, push button on remote within 3 seconds, turn key OFF), but it did not work. Battery in the remote is good (3.26v).

Any ideas on how to get this system to work?

Thanks.

Mike