Question about placement of recolor files

Okay, you change hair color by bringing it into a program like The Gimp or PaintDotNet and tweaking it. I use PaintDotNet. Used to use Gimp but I like PDN better.
HOWEVER... now I am unsure how to get it to show up in the materials tab.
So, I took the Long_Alpha_7 hair adaptation png and made it a really pretty blue in paintdotnet.
... now what? neither the faq or any of the tutorials really tell you that specifically, that I can find.
Perhaps I'm just not absorbing what I'm seeing... it happens.
Someone on here said you can just recolor the png, rename it, then drop it into the folder instead of copying everything... but this doesn't work with just the png file unless I'm missing something.
1. What do I do after coloring the png file and re-saving it as another png?
2. Do I need to alter any other files other than recoloring the png?
3. Anything else I'm missing?
HOWEVER... now I am unsure how to get it to show up in the materials tab.
So, I took the Long_Alpha_7 hair adaptation png and made it a really pretty blue in paintdotnet.
... now what? neither the faq or any of the tutorials really tell you that specifically, that I can find.
Perhaps I'm just not absorbing what I'm seeing... it happens.
Someone on here said you can just recolor the png, rename it, then drop it into the folder instead of copying everything... but this doesn't work with just the png file unless I'm missing something.
1. What do I do after coloring the png file and re-saving it as another png?
2. Do I need to alter any other files other than recoloring the png?
3. Anything else I'm missing?