And when this guy is now a solution and this guy predominates, the solution B will be of a different color. So once again, in acidic solutions, this guy dominates. And in basic solutions, this guy dominates. So, we can look at the ratio of the concentration of this guy to this guy. And when the ratio is ten or above, that means we're going to be of this guy, of this color, so of the active color, because there's much more of this than this in our solution. Now, the opposite is true as well.