Do you have a second 2 -port valve?
yes a ZA6
Good, that makes life easier!
I have just read your other post on the same subject and realised that you had a ZA6 (with the white wire doing nothing) and want to replace it with a ZA5. That's still OK.
You connect new ZA5 Blue to the same terminal as second ZA5 Blue.
You connect new ZA5 Grey to the same terminal as second ZA5 Grey
You connect new ZA5 Orange to the same terminal as second ZA5 Orange
You connect new ZA5 Green/Yellow to the same terminal as second ZA5 Green/Yellow
That leaves the Brown wire.
The Brown wire is the control wire and will connect to the output from the appropriate thermostat. From your other post, that is the HW thermostat. The cable from that stat has two wires (possibly 3). One of these will go to a terminal with nothing else connected. Connect the Brown wire to this terminal.