Following code snippets show how to change the filled color and style of polygon on OpenLayers Map. It is tested and working example. :) Thanks.



           //define style for polygon
            var style_poly =
           {
               strokeColor: "#000000",
               strokeOpacity: 1,
               strokeWidth: 2,
               fillColor: "#00FF00",
               fillOpacity: 0.6
            };
            var polygonLayer = new OpenLayers.Layer.Vector("Polygon Layer");
             //------------set style on layer
             polygonLayer.style=style_green;
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