hmm... okee. I'll play around with it some more.So, firstly, "Add" basically adds white to whatever colour you use and shifts it's hue very slightly.
It can't be used with black because black has no base colour or light, which means it has nothing to shift or lighten.
I find that it never really works properly for pale skin colours, no matter what colour you use, so you might have to mix up a good highlight by yourself (a light, almost-white orange usually works well).
Honestly, I think the one with reduced opacity looks fine; maybe reduce the amount of highlight to just a few slightly brighter dots on more prominent areas (such as the shoulders, cheeks, and maybe a little on the nose)?
