@taun Actually it was outdoors - it's just that I was blessed with an overcast day. The troupe at Apenheul were in a very open area covered with steel (?) mesh. The ones at London were certainly in excellent condition.
I'm not sure on the parents, but to my knowledge all of the grey langurs in Europe are hybrids unfortunately. This makes the fact that London phased-out they're pure Sri Lankan Langurs back in 2010 even more frustrating.