Hi there,
I presume you have a "Renault" Laguna?
Here is a photo of the Renault wiring colours (Note: the tweeter wires have been custom-joined at the front speaker terminals - this is optional):
However, I strongly recommend you purchase an aftermarket "Renault-ISO/ISO-Alpine Harness Adaptors", which connects your Alpine unit directly to your vehicle's factory harness.
These ISO car audio harnesses can be purchased fairly cheaply online or at your local automotive car audio parts centre.
Cheers,