Wire colour to TRS connector, Apple Lightning to 3.5" adapter

The Lightning to 3.5” adapter is a small digital to analogue converterconnected to a "standard headphone" (not for long) tip-ring-sleeve socket. If you cut the socket off (carefully, as the wires are thin and coated in plastic), you can repurpose it.

Here is the map between wire colour and destination on a 3.5” tip-ring-sleeve connector:

If you are going to attach solder to the wires, it's helpful to melt the plastic off them first (with a lighter, for example).