I'm curious which you think is "real" and which has reverted. Presumably you have read the eBay advert and think that "Signalberg Form" is some sort of blue Lithops?

"Signalberg" is actually a name applied to Lithops collected from two locations in Namibia. They used to have their own name but are now just considered to be L. karasmontana var. karasmontana. Thay are both a beige colour with a typical L. karasmontana pattern, not distinguishable from any other L. karasmontana.

I'm not sure where the idea of calling this blue-ish form of Lithops "var. signalberg" came from, presumably just someone trying to make a quick buck on eBay and thought it sounded good. It almost certainly isn't from one of the two locations which would actually carry that name. Personally I don't even think the picture on the eBay auction is L. karasmontana, but is actually a form of L. schwantesii which is known for these blue shades. For what its worth at this early stage, your plants do look like L. karasmontana.

If you do get a really good blue cast on a Lithops it can be striking and well worth growing, the colour will depend strongly on the lighting that your plant gets. It won't actually be blue, Lithops can't make blue pigments, it will be grey with a particular sheen to the surface which appears blue.

How many seeds did you get? The auctions I have seen are for 50 seeds and I would expect 50 seeds from a reputable seller to give 30-40 seedlings without much trouble.

yeah, i did get 50 seeds, but only about 10 or so sprouted, i think it was becuase i sowed them in too porous of a soil and the seeds got lost and i only have two so far that have gotten that greyish color you speak of with the blueish sheen to it, the rest are the brownish color...there are still a couple seedlings that the true leaves havent come through yet

Do post again when the next set of leaves come through and there is a little more detail to see. I'm always interested in how these things turn out.