No, the extra drop where there is no change in color does not count. That extra drop is just done to make sure that the color isn't still changing so you aren't fooled by a partial change. The color change occurs over a little more than one drop typically and it is the end of the color change that represents the true end point for the test. So you count up to and including the last drop that causes a color change but you do not count any drop after that for which there is no change. And by "change" I mean something reasonably substantial. If the hue and most of the saturation have changed and another drop just gets it a little more saturated, you don't have to count that. It's not a huge deal -- accuracy of the test is +/- 1 drop or 10% of the value, whichever is greater.