GuiStyle depth

Hi, i'm using different Guistyle in the same function OnGUI(){ ... }

I'd like to have a specific GuiStyle button over an other Guistyle

 public var mystyledate : GUIStyle;
 public var myStyleNewGame : GUIStyle;
 
 function OnGUI(){
         if(GUI.Button(Rect(xnew,ynew,200,100), "New Game", myStyleNewGame)){ 
             ........
         }
         GUI.Button(Rect(xnew,ynew,100,20),date, mystyledate);
 

I tried mystyledate.depth=-10; but it's not possible.

The only way i found is to write the background button before the top one. But that's not a great solution i think.

Thx