Check for +battery power supply on the wiring connector. One of it should have permanent supply while another one would have same supply when ignition key is turned to 'ACC'. If either one is missing, check for blown fuse along the wiring line.
Sorry I could not give you exact color code of wire because European cars use different color codes from Japanese makes. After market radios usually uses yellow and red for the two power supply lines. Some brands are not specific in using which color for which. Black is the negative ground.
Hope this will help.
bayang2
April 2007