Bug 56637 [Preferences] DialogMessageArea image is too large
Is the background color of the error shown by DialogMessageArea to be changed? Or do you intend to leave it as it is right now? The error message looks a little out of place in the current implementation (being surrounded by white space).
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Sash;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.DialogMessageArea;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.IMessageProvider;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.jface.resource.JFaceColors;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.Assert;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.jface.util.SafeRunnable;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
/**
 * A preference dialog is a hierarchical presentation of preference
 * pages.  Each page is represented by a node in the tree shown
 * on the left hand side of the dialog; when a node is selected, the
 * corresponding page is shown on the right hand side.
 */
public class PreferenceDialog extends Dialog implements IPreferencePageContainer {