That is a blue. Undercolor should be "slate," perhaps what you are calling silvery. Some black birds have white as an undercolor.Just curious, is there anyway to tell a really dark blue and black apart other than test breeding? Is the down underneath a different color or anything? I have a serama cockeral that I'm not sure which it is. It has the lacing you are talking about, and has had me really confused on color. The pic was taken indoors with a flash.