@Dianedm, to also pick up your question from U-Points setting - #2 by Joanna
Unlike ColorEfex 4 – Viveza 2 and 3 have no specific negative control points. Instead you have to use another control point.
In Viv2 it was quite simple to see the constraints of the ‘negative’ control point in the mask view, but very unfortunate (!) that’s no more the case in Viv3. The effect is still there, maybe to a lesser degree.
→ Have you ever tried the Chrominance and Luminance sliders to fine tune the selectivity of the control point masks?