diff --git a/src/Task.Monitor.System/Controls/MessageBox/MessageBox.cs b/src/Task.Monitor.System/Controls/MessageBox/MessageBox.cs
index eb8db96..6e0f568 100644
--- a/src/Task.Monitor.System/Controls/MessageBox/MessageBox.cs
+++ b/src/Task.Monitor.System/Controls/MessageBox/MessageBox.cs
@@ -1,5 +1,6 @@
 using System.Drawing;
 using Task.Monitor.Cli.Utils;
+using Task.Monitor.System.Screens;
 
 namespace Task.Monitor.System.Controls.MessageBox;
 
@@ -14,15 +15,16 @@ public sealed class MessageBox : Control
 
     private bool okFocused = true;
     
-    // TODO: Theme.
-    private Color dialogColour = ConsolePalette.Gray;
-    private Color dialogShadowColour = ConsolePalette.DarkGray;
-    private Color dialogTitleColour = ConsolePalette.White;
-    
     public MessageBox(ISystemTerminal terminal) : base(terminal) { }
 
     public MessageBoxButtons Buttons { get; set; } = MessageBoxButtons.OkCancel;
 
+    public Color DialogBackgroundColour { get; set; } = ConsolePalette.Gray;
+    public Color DialogBorderColour { get; set; } = ConsolePalette.Black;
+    public Color DialogButtonBackgroundColour { get; set; } = ConsolePalette.DarkGray;
+    public Color DialogButtonForegroundColour { get; set; } = ConsolePalette.Black;
+    public Color DialogForegroundColour { get; set; } = ConsolePalette.Black;
+    
     private void DrawButton(
         int x,
         int y,
@@ -38,11 +40,11 @@ private void DrawButton(
             y,
             width,
             height,
-            dialogTitleColour);
+            DialogBackgroundColour);
         
         string centredText = text.CentreWithLength(width);
-        Terminal.BackgroundColor = dialogTitleColour;
-        Terminal.ForegroundColor = ConsolePalette.Black;
+        Terminal.BackgroundColor = DialogButtonBackgroundColour;
+        Terminal.ForegroundColor = DialogButtonForegroundColour;
         
         Terminal.SetCursorPosition(x, y);
 
@@ -58,7 +60,7 @@ private void DrawButton(
                 if (isHighlightChar && selected) {
                     Terminal.ForegroundColor = ConsolePalette.Red;
                     Terminal.Write(ch);
-                    Terminal.ForegroundColor = ConsolePalette.Black;
+                    Terminal.ForegroundColor = DialogButtonForegroundColour;
                     isHighlightChar = false;
                     continue;
                 }
@@ -75,51 +77,51 @@ protected override void OnDraw()
         }
     
         using TerminalColourRestorer _ = new();
-
-        DrawRectangle(
-            X + 1,
-            Y + 1,
-            Width,
-            Height,
-            dialogShadowColour);
         
         DrawRectangle(
             X,
             Y,
             Width,
             Height,
-            dialogColour);
+            DialogBackgroundColour);
         
         int y = Y;
 
-        string centredTitle = Title.CentreWithLength(Width);
-        Terminal.BackgroundColor = dialogTitleColour;
-        Terminal.ForegroundColor = ConsolePalette.Black;
+        int dialogWidth = Width - 2;
+        string title = Title.Length > 0 ? $" {Title} " : string.Empty;
+        int titleLen = Math.Min(title.Length, dialogWidth);
+        int leftDashes = (dialogWidth - titleLen) / 2;
+        int rightDashes = dialogWidth - titleLen - leftDashes;
+
+        Terminal.BackgroundColor = DialogBackgroundColour;
+        Terminal.ForegroundColor = DialogForegroundColour;
         Terminal.SetCursorPosition(X, y);
-        Terminal.Write(centredTitle);
+        Terminal.Write('\u256D');
+        Terminal.Write('\u2500', leftDashes);
+        Terminal.Write(titleLen < title.Length ? title[..titleLen] : title);
+        Terminal.Write('\u2500', rightDashes);
+        Terminal.Write('\u256E');
         
-        string spacer = new(' ', Width);
-        Terminal.BackgroundColor = dialogColour;
-        Terminal.ForegroundColor = ConsolePalette.Black;
+        string spacer = new(' ', dialogWidth);
         Terminal.SetCursorPosition(X, ++y);
-        Terminal.Write(spacer);
-
+        Terminal.Write($"\u2502{spacer}\u2502");
+        
         string[] lines = Text.Split('\n');
         
         for (int n = 0; n < MaxTextLines; n++) { 
             Terminal.SetCursorPosition(X, ++y);
          
             if (n < lines.Length) { 
-                Terminal.Write(lines[n].CentreWithLength(Width));
+                Terminal.Write($"\u2502{lines[n].CentreWithLength(dialogWidth)}\u2502");
                 continue;
             }
          
-            Terminal.Write(spacer);
+            Terminal.Write($"\u2502{spacer}\u2502");
         }
 
         for (int n = 0; n < 2; n++) {
             Terminal.SetCursorPosition(X, ++y);
-            Terminal.Write(spacer);
+            Terminal.Write($"\u2502{spacer}\u2502");
         }
 
         int buttonX = Buttons == MessageBoxButtons.Ok
@@ -127,6 +129,8 @@ protected override void OnDraw()
             : X + (Width / 2 - (ButtonWidth + ButtonGap + ButtonWidth) / 2);
 
         int buttonY = ++y;
+        Terminal.SetCursorPosition(X, buttonY);
+        Terminal.Write($"\u2502{spacer}\u2502");
          
         if (Buttons == MessageBoxButtons.Ok || Buttons == MessageBoxButtons.OkCancel) {
             DrawButton(
@@ -148,14 +152,19 @@ protected override void OnDraw()
                 selected: !okFocused);
         }
 
-        Terminal.BackgroundColor = dialogColour;
-        Terminal.ForegroundColor = ConsolePalette.Black;
+        Terminal.BackgroundColor = DialogBackgroundColour;
+        Terminal.ForegroundColor = DialogForegroundColour;
         Terminal.SetCursorPosition(X, ++y);
-        Terminal.Write(spacer);
+        Terminal.Write($"\u2502{spacer}\u2502");
 
         string help = "Use \u2190 \u2192 and \u21B5 to select";
         Terminal.SetCursorPosition(X, ++y);
-        Terminal.Write(help.CentreWithLength(Width));
+        Terminal.Write($"\u2502{help.CentreWithLength(dialogWidth)}\u2502");
+        
+        Terminal.SetCursorPosition(X, ++y);
+        Terminal.Write('\u2570');
+        Terminal.Write('\u2500', dialogWidth);
+        Terminal.Write('\u256F');
     }
 
     protected override void OnKeyPressed(ConsoleKeyInfo keyInfo, ref bool handled)
diff --git a/src/Task.Monitor.System/ISystemTerminal.cs b/src/Task.Monitor.System/ISystemTerminal.cs
index b36e5d5..6e4773a 100644
--- a/src/Task.Monitor.System/ISystemTerminal.cs
+++ b/src/Task.Monitor.System/ISystemTerminal.cs
@@ -20,6 +20,7 @@ public interface ISystemTerminal
     int WindowWidth { get; }
     int WindowHeight { get; }
     void Write(char ch);
+    void Write(char ch, int count);
     void Write(ReadOnlySpan<char> chars);
     void Write(string message);
     void WriteEmptyLine();
diff --git a/src/Task.Monitor.System/Screens/Screen.cs b/src/Task.Monitor.System/Screens/Screen.cs
index 785b43e..f1b5bdb 100644
--- a/src/Task.Monitor.System/Screens/Screen.cs
+++ b/src/Task.Monitor.System/Screens/Screen.cs
@@ -1,3 +1,4 @@
+using System.Buffers.Text;
 using System.Drawing;
 using Task.Monitor.System.Controls;
 using Task.Monitor.System.Controls.InputBox;
@@ -40,7 +41,6 @@ public override Color BackgroundColour
         get => base.BackgroundColour;
         set {
             base.BackgroundColour = value;
-            messageBox.BackgroundColour = value;
             inputBox.BackgroundColour = value;
         }
     }
@@ -53,6 +53,12 @@ public void Close()
 
     public bool CursorVisible { get; set; } = true;
 
+    public Color DialogBackgroundColour { get => messageBox.DialogBackgroundColour; set => messageBox.DialogBackgroundColour = value; }
+    public Color DialogBorderColour { get => messageBox.DialogBorderColour; set => messageBox.DialogBorderColour = value; }
+    public Color DialogButtonBackgroundColour { get => messageBox.DialogButtonBackgroundColour; set => messageBox.DialogButtonBackgroundColour = value; }
+    public Color DialogButtonForegroundColour { get => messageBox.DialogButtonForegroundColour; set => messageBox.DialogButtonForegroundColour = value; }
+    public Color DialogForegroundColour { get => messageBox.DialogForegroundColour; set => messageBox.DialogForegroundColour = value; }
+    
     private void Focus()
     {
         if (focusedControl != null) {
@@ -87,21 +93,12 @@ public override Color ForegroundColour
         get => base.ForegroundColour;
         set {
             base.ForegroundColour = value;
-            messageBox.ForegroundColour = value;
             inputBox.ForegroundColour = value;
         }
     }
 
     private bool IsActive { get; set; } = false;
-
-    protected override void OnClear()
-    {
-        base.OnClear();
-        
-        messageBox.Clear();
-        inputBox.Clear();
-    }
-
+    
     protected override void OnDraw()
     {
         base.OnDraw();
diff --git a/src/Task.Monitor.System/SystemTerminal.cs b/src/Task.Monitor.System/SystemTerminal.cs
index 02a0968..e79e2f3 100644
--- a/src/Task.Monitor.System/SystemTerminal.cs
+++ b/src/Task.Monitor.System/SystemTerminal.cs
@@ -87,6 +87,14 @@ public void SetCursorPosition(int left, int top)
     public int WindowWidth => Console.WindowWidth;
     public int WindowHeight => Console.WindowHeight;
     public void Write(char ch) => Console.Out.Write(ch);
+
+    public void Write(char ch, int count)
+    {
+        Span<char> buffer = stackalloc char[count];
+        buffer.Fill(ch);
+        Write(buffer);
+    }
+    
     public void Write(ReadOnlySpan<char> chars) => Console.Out.Write(chars);
     public void Write(string message) => Console.Out.Write(message);
     public void WriteEmptyLine() => WriteEmptyLineTo(Console.WindowWidth);
diff --git a/src/taskmon/Gui/MainScreen.cs b/src/taskmon/Gui/MainScreen.cs
index 7c6e533..6020ddc 100644
--- a/src/taskmon/Gui/MainScreen.cs
+++ b/src/taskmon/Gui/MainScreen.cs
@@ -133,6 +133,12 @@ protected override void OnLoad()
 
         BackgroundColour = runContext.AppConfig.DefaultTheme.Background;
         ForegroundColour = runContext.AppConfig.DefaultTheme.Foreground;
+
+        DialogBackgroundColour = runContext.AppConfig.DefaultTheme.HeaderBackground;
+        DialogBorderColour = runContext.AppConfig.DefaultTheme.HeaderForeground;
+        DialogForegroundColour = runContext.AppConfig.DefaultTheme.HeaderForeground;
+        DialogButtonBackgroundColour = runContext.AppConfig.DefaultTheme.BackgroundHighlight;
+        DialogButtonForegroundColour = runContext.AppConfig.DefaultTheme.ForegroundHighlight;
         
         foreach (Control ctrl in Controls) {
             ctrl.BackgroundColour = BackgroundColour;
diff --git a/tests/Task.Monitor.System.Tests/Controls/ForwardingTerminal.cs b/tests/Task.Monitor.System.Tests/Controls/ForwardingTerminal.cs
index b5b7c92..26fd1a3 100644
--- a/tests/Task.Monitor.System.Tests/Controls/ForwardingTerminal.cs
+++ b/tests/Task.Monitor.System.Tests/Controls/ForwardingTerminal.cs
@@ -27,6 +27,7 @@ public sealed class ForwardingTerminal(ISystemTerminal inner) : ISystemTerminal
     public ConsoleKeyInfo ReadKey() => inner.ReadKey();
     public void SetCursorPosition(int left, int top) => inner.SetCursorPosition(left, top);
     public void Write(char ch) => inner.Write(ch);
+    public void Write(char ch, int count) => inner.Write(ch, count);
     public void Write(string message) => inner.Write(message);
     public void WriteEmptyLine() => inner.WriteEmptyLine();
     public void WriteEmptyLineTo(int x) => inner.WriteEmptyLineTo(x);
diff --git a/tests/Task.Monitor.System.Tests/Controls/MessageBox/MessageBoxTests.cs b/tests/Task.Monitor.System.Tests/Controls/MessageBox/MessageBoxTests.cs
index 6e04d02..755e770 100644
--- a/tests/Task.Monitor.System.Tests/Controls/MessageBox/MessageBoxTests.cs
+++ b/tests/Task.Monitor.System.Tests/Controls/MessageBox/MessageBoxTests.cs
@@ -11,7 +11,7 @@ public sealed class MessageBoxTests
 {
     [Fact]
     public void MessageBox_Canary_Test() =>
-        Assert.Equal(15, CanaryTestHelper.GetPropertyCount<MessageBoxControl>());
+        Assert.Equal(20, CanaryTestHelper.GetPropertyCount<MessageBoxControl>());
 
     [Fact]
     public void Should_Construct_Default()
@@ -20,10 +20,15 @@ public void Should_Construct_Default()
         MessageBoxControl control = new(new ForwardingTerminal(terminal.Object));
 
         Assert.Equal(ConsolePalette.Black, control.BackgroundColour);
+        Assert.Equal(MessageBoxButtons.OkCancel, control.Buttons);
         Assert.Empty(control.Controls);
+        Assert.Equal(ConsolePalette.Gray, control.DialogBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, control.DialogBorderColour);
+        Assert.Equal(ConsolePalette.DarkGray, control.DialogButtonBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, control.DialogButtonForegroundColour);
+        Assert.Equal(ConsolePalette.Black, control.DialogForegroundColour);
         Assert.Equal(ConsolePalette.White, control.ForegroundColour);
         Assert.Equal(0, control.Height);
-        Assert.Equal(MessageBoxButtons.OkCancel, control.Buttons);
         Assert.NotNull(control.Name);
         Assert.Equal(MessageBoxResult.None, control.Result);
         Assert.True(0 == control.TabIndex);
@@ -48,6 +53,11 @@ public void Should_Set_Initial_Properties()
         
         MessageBoxControl control = new(new ForwardingTerminal(terminal.Object)) {
             BackgroundColour = ConsolePalette.Gray,
+            DialogBackgroundColour = ConsolePalette.Green,
+            DialogBorderColour = ConsolePalette.Yellow,
+            DialogButtonBackgroundColour = ConsolePalette.Magenta,
+            DialogButtonForegroundColour = ConsolePalette.Red,
+            DialogForegroundColour = ConsolePalette.DarkBlue,
             ForegroundColour = ConsolePalette.Black,
             Buttons = MessageBoxButtons.OkCancel,
             Height = 12,
@@ -60,6 +70,11 @@ public void Should_Set_Initial_Properties()
         };
 
         Assert.Equal(ConsolePalette.Gray, control.BackgroundColour);
+        Assert.Equal(ConsolePalette.Green, control.DialogBackgroundColour);
+        Assert.Equal(ConsolePalette.Yellow, control.DialogBorderColour);
+        Assert.Equal(ConsolePalette.Magenta, control.DialogButtonBackgroundColour);
+        Assert.Equal(ConsolePalette.Red, control.DialogButtonForegroundColour);
+        Assert.Equal(ConsolePalette.DarkBlue, control.DialogForegroundColour);
         Assert.Equal(ConsolePalette.Black, control.ForegroundColour);
         Assert.True(control.Buttons == MessageBoxButtons.OkCancel);
         Assert.Equal(12, control.Height);
diff --git a/tests/Task.Monitor.System.Tests/Controls/RecordingTerminal.cs b/tests/Task.Monitor.System.Tests/Controls/RecordingTerminal.cs
index 0cfb63e..a62e2ba 100644
--- a/tests/Task.Monitor.System.Tests/Controls/RecordingTerminal.cs
+++ b/tests/Task.Monitor.System.Tests/Controls/RecordingTerminal.cs
@@ -40,6 +40,12 @@ public void Write(char ch)
         output.Append(ch);
     }
 
+    public void Write(char ch, int count)
+    {
+        WriteCharCalls++;
+        output.Append(new string(ch, count));
+    }
+
     public void Write(string message)
     {
         WriteStringCalls++;
diff --git a/tests/Task.Monitor.System.Tests/Screens/ScreenTests.cs b/tests/Task.Monitor.System.Tests/Screens/ScreenTests.cs
index 00c7e8a..49f540b 100644
--- a/tests/Task.Monitor.System.Tests/Screens/ScreenTests.cs
+++ b/tests/Task.Monitor.System.Tests/Screens/ScreenTests.cs
@@ -14,7 +14,7 @@ public class TestScreen2(ISystemTerminal systemTerminal) : Screen(systemTerminal
 
     [Fact]
     public void InputBox_Canary_Test() =>
-        Assert.Equal(12, CanaryTestHelper.GetPropertyCount<TestScreen1>());
+        Assert.Equal(17, CanaryTestHelper.GetPropertyCount<TestScreen1>());
 
     [Fact]
     public void Should_Construct_Default()
@@ -25,6 +25,11 @@ public void Should_Construct_Default()
         Assert.Equal(ConsolePalette.Black, testScreen.BackgroundColour);
         Assert.Empty(testScreen.Controls);
         Assert.True(testScreen.CursorVisible);
+        Assert.Equal(ConsolePalette.Gray, testScreen.DialogBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, testScreen.DialogBorderColour);
+        Assert.Equal(ConsolePalette.DarkGray, testScreen.DialogButtonBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, testScreen.DialogButtonForegroundColour);
+        Assert.Equal(ConsolePalette.Gray, testScreen.DialogBackgroundColour);
         Assert.Equal(ConsolePalette.White, testScreen.ForegroundColour);
         Assert.Equal(0, testScreen.Height);
         Assert.NotNull(testScreen.Name);
diff --git a/tests/Task.Monitor.Tests/Gui/HelpScreenTests.cs b/tests/Task.Monitor.Tests/Gui/HelpScreenTests.cs
index b460467..d9bf16d 100644
--- a/tests/Task.Monitor.Tests/Gui/HelpScreenTests.cs
+++ b/tests/Task.Monitor.Tests/Gui/HelpScreenTests.cs
@@ -20,7 +20,7 @@ public HelpScreenTests()
     
     [Fact]
     public void HelpScreen_Canary_Test() =>
-        Assert.Equal(12, CanaryTestHelper.GetPropertyCount<HelpScreen>());
+        Assert.Equal(17, CanaryTestHelper.GetPropertyCount<HelpScreen>());
 
     [Fact]
     public void Constructor_With_Valid_Run_Context_Initialises_Successfully()
@@ -42,6 +42,11 @@ public void Default_Properties_After_Construction_Have_Default_Values()
         Assert.Equal(ConsolePalette.Black, helpScreen.BackgroundColour);
         Assert.Empty(helpScreen.Controls);
         Assert.True(helpScreen.CursorVisible);
+        Assert.Equal(ConsolePalette.Gray, helpScreen.DialogBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, helpScreen.DialogBorderColour);
+        Assert.Equal(ConsolePalette.DarkGray, helpScreen.DialogButtonBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, helpScreen.DialogButtonForegroundColour);
+        Assert.Equal(ConsolePalette.Gray, helpScreen.DialogBackgroundColour);
         Assert.Equal(ConsolePalette.White, helpScreen.ForegroundColour);
         Assert.Equal(0, helpScreen.Height);
         Assert.NotNull(helpScreen.Name);
diff --git a/tests/Task.Monitor.Tests/Gui/MainScreenTests.cs b/tests/Task.Monitor.Tests/Gui/MainScreenTests.cs
index 3be6d18..ce5695c 100644
--- a/tests/Task.Monitor.Tests/Gui/MainScreenTests.cs
+++ b/tests/Task.Monitor.Tests/Gui/MainScreenTests.cs
@@ -21,7 +21,7 @@ public MainScreenTests()
 
     [Fact]
     public void MainScreen_Canary_Test() =>
-        Assert.Equal(12, CanaryTestHelper.GetPropertyCount<MainScreen>());
+        Assert.Equal(17, CanaryTestHelper.GetPropertyCount<MainScreen>());
 
     [Fact]
     public void Constructor_With_Valid_Run_Context_Initialises_Successfully()
@@ -47,6 +47,11 @@ public void Default_Properties_After_Construction_Have_Default_Values()
         Assert.Equal(ConsolePalette.Black, mainScreen.BackgroundColour);
         Assert.NotEmpty(mainScreen.Controls);
         Assert.True(mainScreen.CursorVisible);
+        Assert.Equal(ConsolePalette.Gray, mainScreen.DialogBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, mainScreen.DialogBorderColour);
+        Assert.Equal(ConsolePalette.DarkGray, mainScreen.DialogButtonBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, mainScreen.DialogButtonForegroundColour);
+        Assert.Equal(ConsolePalette.Gray, mainScreen.DialogBackgroundColour);
         Assert.Equal(ConsolePalette.White, mainScreen.ForegroundColour);
         Assert.Equal(0, mainScreen.Height);
         Assert.NotNull(mainScreen.Name);
diff --git a/tests/Task.Monitor.Tests/Gui/SetupScreenTests.cs b/tests/Task.Monitor.Tests/Gui/SetupScreenTests.cs
index 6ebeee8..73d163a 100644
--- a/tests/Task.Monitor.Tests/Gui/SetupScreenTests.cs
+++ b/tests/Task.Monitor.Tests/Gui/SetupScreenTests.cs
@@ -21,7 +21,7 @@ public SetupScreenTests()
 
     [Fact]
     public void SetupScreen_Canary_Test() =>
-        Assert.Equal(12, CanaryTestHelper.GetPropertyCount<SetupScreen>());
+        Assert.Equal(17, CanaryTestHelper.GetPropertyCount<SetupScreen>());
 
     [Fact]
     public void Constructor_With_Valid_Run_Context_Initialises_Successfully()
@@ -43,6 +43,11 @@ public void Default_Properties_After_Construction_Have_Default_Values()
         Assert.Equal(ConsolePalette.Black, setupScreen.BackgroundColour);
         Assert.NotEmpty(setupScreen.Controls);
         Assert.True(setupScreen.CursorVisible);
+        Assert.Equal(ConsolePalette.Gray, setupScreen.DialogBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, setupScreen.DialogBorderColour);
+        Assert.Equal(ConsolePalette.DarkGray, setupScreen.DialogButtonBackgroundColour);
+        Assert.Equal(ConsolePalette.Black, setupScreen.DialogButtonForegroundColour);
+        Assert.Equal(ConsolePalette.Gray, setupScreen.DialogBackgroundColour);
         Assert.Equal(ConsolePalette.White, setupScreen.ForegroundColour);
         Assert.Equal(0, setupScreen.Height);
         Assert.NotNull(setupScreen.Name);