timing of paintwork

can anyone put a date on when metallic paint was introduced on defenders also when coloured coded wheel arches were included
just trying to date an odd advert

according to the Defender timeline (in LRW april '06) in the piccies there are body coloured wheel arches in the picture of the 90 from 1984. there arent any other pictures where they can be seen before then. sorry it doesnt really narrow down when ur advert is from! sorry nothing about metallic paint