I just received a nice example of a Waterman 92 in the steel quartz color. That is actually what Waterman called the color. An earlier color, used in the 94 series of pens, is often called "steel quartz" - however, Waterman called it either "grey" or "grey pearl". The Davis/Lehrer book calls it "silver pearl".
Here is a comparison of the two colors. The top pen is a 94 in grey pearl, the lower pen is a 92 in steel quartz.