GradientPaint gp = new GradientPaint(new Point(), new Color(255, 255, 255), new Point(), new Color(240, 240, 240));
DialBackground sdb = new DialBackground(gp);
GradientPaintTransformType gradientPaintTransformType=GradientPaintTransformType.HORIZONTAL;
sdb.setGradientPaintTransformer(new StandardGradientPaintTransformer(gradientPaintTransformType));
plot.addLayer(sdb);
increment = (upper-lower)/4;
StandardDialScale scale=null;
scale = new StandardDialScale(lower, upper, 115.0,-50.0, increment, minorTickCount);