Using Simgaroop's Hair Colour Actions

I'm new to hair retexturing and using colour actions on them, so I need to ask a probably very obvious question about using those actions. I have some of Neena's textures to work from (someone uploaded them on a thread at GoS), and Simgaroop's colour actions, but I have no idea how to apply them. Is there an order I need to work in? I tried applying the black colour action to the Neena blond hair texture (sort of pale yellow) I used to retexture, and the end result was more like dark brown. I figure I'm definitely doing something wrong. Should I be using a different hair texture to start from? Am I missing a step? Please help!

Thank you in advance to anyone who can help this hopeless beginner.

Bonus question: Are there any meshes out there that haven't already been Neena'd that you'd like to recommend for recolour? I'm trying to find a couple of good options for my secret santa and it seems like most hair meshes already have been given the Maxis-match treatment. Any oldies but goodies or otherwise overlooked meshes out there that you love?