Open the png with Photo Viewer,
Open Color and Appearance by pasting rundll32.exe shell32.dll,Control_RunDLL desk.cpl,Advanced,@Advanced into a Run box,
then put those and some other windows all on the screen, (and keep opening Start)
then start fiddling with color mixer til you get it right. It's a bit tricky but you'll get it.
(The taskbar will always be a couple shades darker unless you apply 'Taskbar Color Override' Reg hack)
Wow, thanks, that's way easier than searching around in the registry.
It turns out that it kind of fixed it. The color mixer is awesome for fine tuning the exact color I wanted. To bad the menu didn't include translucency too, but I tweaked the darkness and saturation to get close to the desired effect. The active green border above did change, but only the top border changed and the other 3 borders turned pink, lol. The inactive border color is now white on the same 3 sides, and the top also changed to the color selected in the color chooser. The good news is, the pink matches my background better than the green