[Tibbs]

I would like to replace this large Truespeed plug with a thinner one plus I want to add to the cable length.
In my pic the truespeed wires are L =green/yellow R=Blue  Earth=brown, the scalextric controller has red green and black wires.
Can someone please advise what wires  connect to what when I join them up?
It is scalextrix analouge Sport track.
   

Thanks Tony