#target Photoshop 
 
main(); 
 
function main() { 
     
        var myImage = app.activeDocument; 
         
        var myPaths = myImage.pathItems; 
         
        var myAlphaChannel = myImage.channels.add(); 
        myAlphaChannel.name = test"; 
         
        for (i = 0; i < myPaths.length; i++){ 
             
                if (myPaths[i].kind == PathKind.CLIPPINGPATH){ 
                         
                        var mySelection = myPaths[i].makeSelection (); 
                     } 
                 
            } 
         
        mySelection.fill ({red:255, green:0, blue:0}, ColorBlendMode.NORMAL, 100, true); 
         
     } 

#target Photoshop  
  
main();  
  
function main() {  
      
	var myImage = app.activeDocument;  
	  
	var myAlphaChannel = myImage.channels.add();  
	myAlphaChannel.name = "test";  
 
	myImage.activeChannels = [ myAlphaChannel ]; 
	 
	var colour = new SolidColor(); 
	colour.gray.gray = 8.0; 
	 
	var myPaths = myImage.pathItems;  
	  
	for (i = 0; i < myPaths.length; i++){  
		if (myPaths[i].kind == PathKind.CLIPPINGPATH){  
			 myPaths[i].makeSelection ();  
	//		 myPaths[i].fillPath( colour ); 
		} 
	}  
	try { 
		app.activeDocument.selection.bounds; 
		myImage.selection.fill ( colour );  
	} catch(e) { 
		$.writeln(e); 
	} 
	app.activeDocument.selection.deselect(); 
	app.activeDocument.activeChannels = app.activeDocument.componentChannels; 
	myAlphaChannel.visible = true; 
}