I am assuming from your description that the driver's side window works, so that would indicate that the window-lift relay is working.
There should be a brown/yellow and a black wire feeding the passenger switch. Do you see power across these two? If yes, the feed from the fuse box and the ground connection are ok.
Are you checking the wires inside the door or inside the car? If you are checking inside the door there could be a break where the loom feeds through to the door.
I only have circuit diagrams for the F (do you have an F or TF?) They don't show red or blue wires, only the grey/pink and grey/black running from the switch to the motor, so if you have an F it could be that there has been a break in the past that has been repaired.
Steve