Illustrator adds gray between gradient stops

I have a 2-stop linear gradient I created by starting with the same color on each stop.  Then I opened one stop to see the color in the picker, and without changing hue, pulled the color to the lower right a bit, thus decreasing value and increasing saturation.  The picker clearly shows an clean, even gradient between the two color points, with no gray in between (none necessary to calculate the gradient), yet Illustrator puts a band of gray in the middle of the transition.  Does anyone know a work around for this bug, short of choosing another color?  Thanks!