I'm not sure how to tell you exactly what the color is, there is really no documentation on this (as you may have already figured out). My car also came from the Dallas assembly plant, so it's safe to say that yours should be painted the same color. It's a tan color with a hint of green in it.
You can see where the underside had overspray on it. I showed all of these pictures to the body shop that is painting our '60 Starliner, they aren't going to mask the bottom side when spraying color on the car in hopes that it oversprays similarly.
Let me see if I can grab you a paint chip from the wheel well area, because I'm going to paint both of the wheel wells black.