It is because of the finding of these beads in the NW, up to Alaska and down into CA, that they are popularly called "Russian" beads.

The beads were actually manufactured in Bohemia/Czechoslovakia, in the 19th C. If they had any part in the Fur Trade, it would have transpired late in that time. In earlier years, these beads were presumed to be older than is the case (as often happens). Here in N. CA, they are often recovered with cornaline d'Aleppo (Venetian white-heart) beads, that post-date ca. 1830.

I am not aware that anyone has seriated "Russian" beads, with any indication that any particular style or color is earlier than any other(s). I think they are too recent for archaeology to help much; and they don't appear on many (or any?) sample cards I can think of that are dated.

I would not ascribe any meaning to the lighter colored base layers. These exist to make the blue glass appear brighter and paler.

In the forty years I have been documenting beads, of this type, I have seen various blues, turquoise blue, teal blue (almost green), golden yellow, red, violet, brown, black, white, and colorless specimens. I think brown is among the more rare colors—and I am pleased I have a strand of them, from W. Africa.

Jamey