Tapio Wirkkala Smokey Blue

Obviously the maker is known. My question is about the color. I have looked high and low to find any other pieces with this tremendously smokey dark blue color. There are lots of blue colors but this is truly different. You can almost not see through it unless there is very bright lighting behind it...so much so that if it isn't lit from behind, it appears to be black. Does anyone know if this is special in any way?