I think there are 2 color variations of this Tropicana $1 chip on the "Sun" Blue Chip Co. mold.
The first & common one has the light tan inlay, and the second is the grayish (white roach) variation you show.

Also, Joe Pavlik posted a picture of the variation (he calls it bluish color). See --
http://www.thechipboard.com/index.cgi/page/1/md/read/id/1264462/sbj/new-vegas-release-tropicana/
It turns out this wasn't the newest issue (hasn't been released yet), but is still a variation, IMO.

One possibility is that the inlay was produced using a 4-color CMYK printing process and one of the colors was not applied to this run of inlays.
For example, if the C=Cyan, M=Magenta, and K=Black were applied through individual screens, but the Y=Yellow layer was not, a final result might look like the inlay you show. (Not sure on this, but possible.)

Look at the inlay using a magnifying glass and compare to the other inlay color. Do you see yellow "dots" on the light tan one, but no yellow dots on the "white roach" one? If so, the variation might be considered a printing manufacturer's error chip, and is probably rarer (much rarer?) than the correct one.

Various printing errors do occur, and some do slip through quality control and make it to the tables. It's also possible that it is a supplemental production run, with an intentional change in the inlay color, in which a large quantity may exist. Time will tell if this variation is common or not.