TimB, with rare exceptions, Morgans new and old have generally followed the BS wiring codes as available as download
here.
The basic range of colours including light green, slate, pink, orange, brown and purple are extended to provide more accuracy to application with a second tracer colour.
Most are abbreviated to single letter + another for tracer if present. Note some colours use the following less obvious letters though.
U: blue
N: brown
K: pink
L.G: light green
