Ya, I thought the decimal point was the problem too, but I've tried copying and pasting the density to know avail. The funny thing is, I can change the color on either entry either entry and its changes the same elements. Only one of the colors for each value is actually shown on in the model form what I can tell.
To attempt to recreate this, you might try changing densities (or temp. or pressure, I've had the same things happen with them) a few times, leaving some element with the original value and the changing some back to it.
Of course, this isn't a very important issue... it just annoys me.