Bounds bBounds = new Bounds(x, x, y, y);
Iterator<DXFLayer> j = doc.getDXFLayerIterator();
while (j.hasNext()) {
DXFLayer l = j.next();
//set color to gray
l.setColor(8);
Iterator<String> ti = l.getDXFEntityTypeIterator();
while (ti.hasNext()) {
String type = (String) ti.next();
Iterator<DXFEntity> ei = l.getDXFEntities(type).iterator();
while (ei.hasNext()) {
DXFEntity entity = ei.next();
//set to gray