Yes, there are. Without getting into a discussion of what was built using traditional wooden framed building techniques and what were prefabricated laminates, some of the 1950s stock were turned out in the 'silver' livery along with the A and C class locomotives, the class leaders of the B, E, G classes and the 4w luggage vans. For certain there is photographic evidence of one or more 1429 series 7-compartment standard coaches in silver and some others if I recall. 'Unfortunately', I'm not at home and cannot access my iMac as I physically disconnected it having been hit by lighting last month
Some indirect evidence of a silver composite laminate on John's post here
http://irishrailwaymodeller.com/showthread.php/1367-Irish-Railway-News-1957-60?p=20242&highlight=Silver+livery+coach#post20242
Silver 4w Luggage 'Hooded' Van
There's a photo of a laminate on the site somewhere, can't find it
Good old Ernie,
The odd man out is unquestionably a 1429 series coach
The rest are green however. The silver would have been most common from 1955-1960ish only