Per Rich Stoer: "Here's an Imperial candlestick we came across on eBay in a color we didn't know existed. According to what I could find out this color must be "Blue Slag" which was made circa 1965. In Volume Two we state that this candlestick may have been made into the early fifties. If I've got the right color, apparently it was also made in the '60s."
Per Tom Felt: "My guess is that this was a sample or trial piece that didn't go into full production. According to Nathan Taves and Don Jennings' Slag & Marble Glass, Imperial only made blue slag very briefly in the mid-1960s and primarily only in ash trays (so briefly, that it doesn't appear in any of the catalogs or price lists that I have from that period) -- and then experimented again with it in the Lenox years. I suspect that they pulled this mold out again during one of those time frames just to test it."