如果不设置，那么出来的位置会在左上角，setLocation(new Point(610,100));方法可以将ColorDialog设置带任意绝对位置
if (colorDialog == null) {
Shell shell = new Shell(com.getShell(),SWT.DIALOG_TRIM | SWT.APPLICATION_MODAL);
shell.setLocation(new Point(610,100));
colorDialog = new ColorDialog(shell, SWT.CENTER);
}