Retrieve layers color value.

getLayersColor.jsx

//Need to include stdlibs in xtools. You can reference below link.
//http://ps-scripts.sourceforge.net/xtools.html

#include "stdlib.js"

var desc = Stdlib.getLayerDescriptor(
		app.activeDocument,
		app.activeDocument.activeLayer
		);
var adjs = desc.getList(cTID('Adjs'));

var clrDesc = adjs.getObjectValue(0);
var color= clrDesc.getObjectValue(cTID('Clr '));

var r = Math.round(color.getDouble(cTID('Rd  ')));
var g = Math.round(color.getDouble(cTID('Grn ')));
var b = Math.round(color.getDouble(cTID('Bl  ')));

alert(r+" "+g+" "+b);