KML file loaded with no filling color, just outline color only

I built the Cesium-Kml branch and used the following code to load a kml\kmz file:

var kmlDataSource = new Cesium.KmlDataSource();




the code worked perfectly but it just draw the outlines only without the filling color, when i tried to load the same drawings but in KMZ file format it loads successfully with all the fill and outline colors.

so can anyone help me solving this problem or any workaround except using the (CZML-Writer) to write the czml file which is a native drawing format for cesium, i have just limited time to accomplish the task.