Referencing a MC within another object AS3

Hello, I’m fairly new to AS3 and this error is driving me crazy, Basically my setup is this:

I’ve got a button which is called “playBtn”, within this i have a MC called “btnlarge”, If i remove the .btnlarge from the below code, then the “playBtn” is coloured correctly in my player,

var sColor:ColorTransform = player.playBtn.btnlarge.transform.colorTransform;
sColor.color = scolour;
player.playBtn.btnlarge.transform.colorTransform = sColor;

however with it in… i’m obviously wanting the btnlarge MC to be coloured, but this isn’t happening and its throwing me this error:

ReferenceError: Error #1069: Property btnlarge not found on flash.display.SimpleButton and there is no default value. at f4::Player/skinCompleteEvent()

Is there something really obvious i’m doing wrong? I’ve tried changing the “playBtn” into a MC and all kinds of things, but nothing seems to work, i can’t seem to reference anything within another object.

Thanks
Mark