There's some difference of opinion on that whether that was a common practice. There are some works of period art which show people wearing what appears to be the configuration you are describing - a colored upper body, with little metal-looking dots, and metalic lower body.
Some people interpret this as a placate worn over a brig. Some see it as a full cuirass, with a fabric covered breastplate.
As for your question: As far as I've seen, rear placates are usually "Flatter" than fronts.
--------------------
Geoffrey Bourrette
Man At Arms