a standard pace 4000 will work with either type of remote - assuming you have one with the silver volume channel buttons which do NOT wrap around the sides of the box then it souldn't matter if it's a blue one or a grey one for the 4000; however only the grey one will work on a 1000. However, you can convert blue to grey by removing a link on the board (looks like a surface mount resistor with '0' on the top, i.e. is effectively a link) which goes to one of the pins on the right of the chip on the remote (pin 17? can't remember), and vice versa make a grey into a blue by soldering the link in.