Hi Charithea,
Yes, I've always liked the look of brown coloured Dutch Iris but it took ages to get any! On the packs of "Mixed Dutch Iris" there was always a picture with blue, yellow, white and brown flowers but there was never a brown one in the pack! 'Thunderbolt' was the first one I got from a friend back in the late 1990s, I think. The others have become available commercially in recent years here.
cheers
fermi