ActionScript 3.0 :: MovieClip Changing From Black To White On Rollover

I have got one movieclip that is a square it is 20 x 20 the movieclip changes from black to white when you roll over it and remains white. The problem I have is that I need 3000 of them and putting them in a grid format so the user can create there own black and white mosaic. But when I do it only the newest square added to the stage changes colour i think i have gone down the wrong path and I've hit a dead end.

This is my code (Which im 90% is all wrong):
PHP Code:
stop();
var sqreArray:Array = new Array();
for (var i:int = numChildren - 0;
i >= 3000; i++) {
var child:DisplayObject = getChildAt(i);
[Code] .....