DHTMLXGRID header problem

I am using dhtmlxgrid but header is having light gray color instead of sky blue color and also having some alignment problem as attached in image.
code is as below.

mygrid = new dhtmlXGridObject('mygrid_container');
mygrid.setImagePath("/e1/images/dhtmlx/");
mygrid.setHeader("Code,Description,Start Date,End Date,Type,Score");
mygrid.attachHeader("#text_filter,#text_filter,#text_filter,#text_filter,#text_filter,#text_filter");
mygrid.setColAlign("left,left,left,left,left,left");
mygrid.setColSorting("str,str,str,str,str,int");
mygrid.setColTypes("ro,ro,ro,ro,ro,dyn");
mygrid.attachEvent("onRowSelect", doOnRowSelected);
mygrid.setSkin("dhx_skyblue");
mygrid.init();
mygrid.enablePaging(true, 5, 10, "pagingArea", true, "infoArea");
mygrid.setPagingSkin("bricks");
mygrid.loadXML("pupilMonitoringAction.do?mode=listMonitoringView");


is having light gray color instead of sky blue color
Css links are broken.
Be sure that all necessary css files are included and location of css files in relation to the imgs folder is the same as in the original package ( if relative location was changed - paths need to be updated in the css file accordingly )

Thanks and I have checked all image location are updated and also all other images of grid are working properly example down arrow and up arrow etc…