Hi, that's quite a vague question, what do you mean by "what the wires are for"? ... obviously they are all lives distributed through the switch from the main feed which is the brown wire coming from maxi fuse MF5 engine compartment, the others are going to the fascia fusebox where are splitted toward various circuits as follows:
-green/white to accessory relay
-white/red to F17
-white to F15,16,18
-yellow to F1, 13, 14 and sattelite fusebox F3, 4, 5
to your question i can't answer anything else, if you want to know something specific ask the right question saying exactly what are you after and i'll try to help