Radio wiring - pre bodged

Hey guys. Can anyone tell me which of these wires does what in my pic? As I understand the white is a 12v switch from the head unit to turn on the amp but I can't figure the other 5.

The car is a 2004 a3 se (8PA)

The guy who owned the car previously had just bodged it together just to get the front speakers going from a trashy Sony unit. I've got my pioneer going instead thru the same speakers, and fitted a proper iso plug in between (he connected straight thru) and the wires in my hand were taped up. Got the aerial sorted, gonna wire a switch feed to it when I get the rest going.

Any help will be appreciated.

Cheers guys.

for future reference guys (if anyone is interested) green and yellow are left and right (unsure which way round) the gray is the common return for both, white is definitely the switch and the black & brown I just left connected together, presumably a ground to the amp or something.

to get it working I found 2 RCA leads, chopped the male ends off and stripped them back and connected the feed from one to green, the other yellow and both the returns to gray.

the RCA end can be plugged into a pre-out on your radio or if you dont have any you can buy an adapter (they had some in halfords) that connects onto the grey and whites (which would usually be the rear speakers and thats on the back of the radio, not the small cable in my hand above) and at the other end is a female RCA, plug them in

And finally the blue remote wire from the radio to the white wire in my hand and hopefully you should be away!

you will also need a "fakra" iso radio adaptor which also needs to be wired into the blue from the radio.

i used spade crimp connectors with the sheath around so that if i ever needed to change again it should be a minor job. although in theory depending on the radio it should just be a case of plugging in a wiring harness if its needed.

Its abit of a bodge job by myself but certainly miles better than the last fool.

i doubt anybody will be interested really but i can upload photos if anyone wants

next job is to get a switch feed to it before i forget to turn it off...