Global and setRGB help please

I’ve got a movieclip with another movieclip inside named fill that has a shape. The main movieclip get’s duplicated and the duplicate is set to _global.current. As long as no other duplicate movieclip is drpped on the target, then this movie is _global.current. I’m trying to set the color of _global.current with a button, but I am having no luck. I can set the movieclip that spaned the duplicate’s color, so I know the button can do it.
Any ideas for a relative noobie,