There were a couple of different grey colors throughout the fox years. They are so similar that it would be nearly impossible to tell one from the other seperately, but put them next to each other and you can see the difference.
When I got my old 90' GT, it was missing the passenger side armrest. I bought a set of used ones on Ebay and when I got them, they were a different shade than the drivers-side armrest I already had, as well as the rest of the interior.
I don't know if this was a year-to-year thing, or a model-by-model thing, nor do I know the exact names of the colors, but there definately were different greys. One is a little more blue-ish and the other is a little warmer, like the tan-like hue that you're describing.
Hope this helps!