diff --git a/Bloxstrap/App.xaml b/Bloxstrap/App.xaml
index 685eaad..2029b34 100644
--- a/Bloxstrap/App.xaml
+++ b/Bloxstrap/App.xaml
@@ -11,6 +11,7 @@
             <ResourceDictionary.MergedDictionaries>
                 <ui:ThemesDictionary Theme="Dark" />
                 <ui:ControlsDictionary />
+                <ResourceDictionary x:Name="CustomTheme" Source="UI/Style/Dark.xaml" /> <!-- NOTE: WpfUiWindow::ApplyTheme relies on this order. If you plan to change the order, please update the index in the function. -->
                 <ResourceDictionary x:Name="Default" Source="UI/Style/Default.xaml" />
             </ResourceDictionary.MergedDictionaries>
 
diff --git a/Bloxstrap/Bloxstrap.csproj b/Bloxstrap/Bloxstrap.csproj
index 361ca8f..8598d98 100644
--- a/Bloxstrap/Bloxstrap.csproj
+++ b/Bloxstrap/Bloxstrap.csproj
@@ -25,6 +25,8 @@
     <Resource Include="Resources\MessageBox\Information.png" />
     <Resource Include="Resources\MessageBox\Question.png" />
     <Resource Include="Resources\MessageBox\Warning.png" />
+    <EmbeddedResource Include="UI\Style\Editor-Theme-Dark.xshd" />
+    <EmbeddedResource Include="UI\Style\Editor-Theme-Light.xshd" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/Bloxstrap/UI/Elements/Base/WpfUiWindow.cs b/Bloxstrap/UI/Elements/Base/WpfUiWindow.cs
index db06e7f..9802ab1 100644
--- a/Bloxstrap/UI/Elements/Base/WpfUiWindow.cs
+++ b/Bloxstrap/UI/Elements/Base/WpfUiWindow.cs
@@ -18,9 +18,15 @@ namespace Bloxstrap.UI.Elements.Base
 
         public void ApplyTheme()
         {
+            const int customThemeIndex = 2; // index for CustomTheme merged dictionary
+
             _themeService.SetTheme(App.Settings.Prop.Theme.GetFinal() == Enums.Theme.Dark ? ThemeType.Dark : ThemeType.Light);
             _themeService.SetSystemAccent();
 
+            // there doesn't seem to be a way to query the name for merged dictionaries
+            var dict = new ResourceDictionary { Source = new Uri($"pack://application:,,,/UI/Style/{Enum.GetName(App.Settings.Prop.Theme.GetFinal())}.xaml") };
+            Application.Current.Resources.MergedDictionaries[customThemeIndex] = dict;
+
 #if QA_BUILD
             this.BorderBrush = System.Windows.Media.Brushes.Red;
             this.BorderThickness = new Thickness(4);
diff --git a/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml b/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml
index 4c4cdf4..f27f802 100644
--- a/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml
+++ b/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml
@@ -39,6 +39,7 @@
             Grid.Row="1"
             Margin="10,10,10,0"
             ShowLineNumbers="True"
+            Style="{StaticResource NewTextEditor}"
             SyntaxHighlighting="XML"
             TextChanged="OnCodeChanged" />
 
diff --git a/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml.cs b/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml.cs
index 63acc34..5888c63 100644
--- a/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml.cs
+++ b/Bloxstrap/UI/Elements/Editor/BootstrapperEditorWindow.xaml.cs
@@ -1,8 +1,11 @@
 using System.Windows.Input;
+using System.Xml;
 
 using ICSharpCode.AvalonEdit.CodeCompletion;
 using ICSharpCode.AvalonEdit.Document;
 using ICSharpCode.AvalonEdit.Editing;
+using ICSharpCode.AvalonEdit.Highlighting.Xshd;
+using ICSharpCode.AvalonEdit.Highlighting;
 
 using Bloxstrap.UI.Elements.Base;
 using Bloxstrap.UI.ViewModels.Editor;
@@ -146,6 +149,18 @@ namespace Bloxstrap.UI.Elements.Editor
 
             UIXML.Text = viewModel.Code;
             UIXML.TextArea.TextEntered += OnTextAreaTextEntered;
+
+            LoadHighlightingTheme();
+        }
+
+        private void LoadHighlightingTheme()
+        {
+            string name = $"Editor-Theme-{App.Settings.Prop.Theme.GetFinal()}.xshd";
+            using Stream xmlStream = Resource.GetStream(name);
+            using XmlReader reader = XmlReader.Create(xmlStream);
+            UIXML.SyntaxHighlighting = HighlightingLoader.Load(reader, HighlightingManager.Instance);
+
+            UIXML.TextArea.TextView.SetResourceReference(ICSharpCode.AvalonEdit.Rendering.TextView.LinkTextForegroundBrushProperty, "NewTextEditorLink");
         }
 
         private static string ToCRLF(string text)
diff --git a/Bloxstrap/UI/Style/Dark.xaml b/Bloxstrap/UI/Style/Dark.xaml
new file mode 100644
index 0000000..2c7b0cb
--- /dev/null
+++ b/Bloxstrap/UI/Style/Dark.xaml
@@ -0,0 +1,5 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <SolidColorBrush x:Key="NewTextEditorBackground" Color="#2D2D2D" />
+    <SolidColorBrush x:Key="NewTextEditorForeground" Color="White" />
+    <SolidColorBrush x:Key="NewTextEditorLink" Color="#3A9CEA" />
+</ResourceDictionary>
\ No newline at end of file
diff --git a/Bloxstrap/UI/Style/Default.xaml b/Bloxstrap/UI/Style/Default.xaml
index b2a646a..9083a8b 100644
--- a/Bloxstrap/UI/Style/Default.xaml
+++ b/Bloxstrap/UI/Style/Default.xaml
@@ -1,6 +1,7 @@
 <ResourceDictionary
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:avalonedit="http://icsharpcode.net/sharpdevelop/avalonedit"
     xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml">
 
     <!--  Taken from DefaultUiCardExpanderStyle  -->
@@ -151,4 +152,38 @@
             </Setter.Value>
         </Setter>
     </Style>
+
+    <!--  Taken from https://github.com/icsharpcode/AvalonEdit/blob/30cad99ce905412ed5f5e847e3c00e72e69aee77/ICSharpCode.AvalonEdit/TextEditor.xaml  -->
+    <Style x:Key="NewTextEditor" TargetType="{x:Type avalonedit:TextEditor}">
+        <Setter Property="Foreground" Value="{DynamicResource NewTextEditorForeground}" />
+        <Setter Property="Background" Value="{DynamicResource NewTextEditorBackground}" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="{x:Type avalonedit:TextEditor}">
+                    <Border
+                        Background="{TemplateBinding Background}"
+                        BorderBrush="{TemplateBinding BorderBrush}"
+                        BorderThickness="{TemplateBinding BorderThickness}"
+                        CornerRadius="4">
+                        <ScrollViewer
+                            Name="PART_ScrollViewer"
+                            Padding="{TemplateBinding Padding}"
+                            HorizontalContentAlignment="Left"
+                            VerticalContentAlignment="Top"
+                            CanContentScroll="True"
+                            Content="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TextArea}"
+                            Focusable="False"
+                            HorizontalScrollBarVisibility="{TemplateBinding HorizontalScrollBarVisibility}"
+                            VerticalScrollBarVisibility="{TemplateBinding VerticalScrollBarVisibility}" />
+                    </Border>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="WordWrap" Value="True">
+                            <Setter TargetName="PART_ScrollViewer" Property="HorizontalScrollBarVisibility" Value="Disabled" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
 </ResourceDictionary>
\ No newline at end of file
diff --git a/Bloxstrap/UI/Style/Editor-Theme-Dark.xshd b/Bloxstrap/UI/Style/Editor-Theme-Dark.xshd
new file mode 100644
index 0000000..5f5da3e
--- /dev/null
+++ b/Bloxstrap/UI/Style/Editor-Theme-Dark.xshd
@@ -0,0 +1,63 @@
+<SyntaxDefinition name="XML" extensions=".xml;.xsl;.xslt;.xsd;.manifest;.config;.addin;.xshd;.wxs;.wxi;.wxl;.proj;.csproj;.vbproj;.ilproj;.booproj;.build;.xfrm;.targets;.xaml;.xpt;.xft;.map;.wsdl;.disco;.ps1xml;.nuspec" xmlns="http://icsharpcode.net/sharpdevelop/syntaxdefinition/2008">
+	<Color foreground="#529955" name="Comment" exampleText="&lt;!-- comment --&gt;" />
+	<Color foreground="White" name="CData" exampleText="&lt;![CDATA[data]]&gt;" />
+	<Color foreground="White" name="DocType" exampleText="&lt;!DOCTYPE rootElement&gt;" />
+	<Color foreground="White" name="XmlDeclaration" exampleText='&lt;?xml version="1.0"?&gt;' />
+	<Color foreground="#569CD6" name="XmlTag" exampleText='&lt;tag attribute="value" /&gt;' />
+	<Color foreground="#9CDCFE" name="AttributeName" exampleText='&lt;tag attribute="value" /&gt;' />
+	<Color foreground="#CE9178" name="AttributeValue" exampleText='&lt;tag attribute="value" /&gt;' />
+	<Color foreground="White" name="Entity" exampleText="index.aspx?a=1&amp;amp;b=2" />
+	<Color foreground="White" name="BrokenEntity" exampleText="index.aspx?a=1&amp;b=2" />
+	
+	<RuleSet>
+		<Span color="Comment" multiline="true">
+			<Begin>&lt;!--</Begin>
+			<End>--&gt;</End>
+		</Span>
+		<Span color="CData" multiline="true">
+			<Begin>&lt;!\[CDATA\[</Begin>
+			<End>]]&gt;</End>
+		</Span>
+		<Span color="DocType" multiline="true">
+			<Begin>&lt;!DOCTYPE</Begin>
+			<End>&gt;</End>
+		</Span>
+		<Span color="XmlDeclaration" multiline="true">
+			<Begin>&lt;\?</Begin>
+			<End>\?&gt;</End>
+		</Span>
+		<Span color="XmlTag" multiline="true">
+			<Begin>&lt;</Begin>
+			<End>&gt;</End>
+			<RuleSet>
+				<!-- Treat the position before '<' as end, as that's not a valid character
+				     in attribute names and indicates the user forgot a closing quote. -->
+				<Span color="AttributeValue" multiline="true" ruleSet="EntitySet">
+					<Begin>"</Begin>
+					<End>"|(?=&lt;)</End>
+				</Span>
+				<Span color="AttributeValue" multiline="true" ruleSet="EntitySet">
+					<Begin>'</Begin>
+					<End>'|(?=&lt;)</End>
+				</Span>
+				<Rule color="AttributeName">[\d\w_\-\.]+(?=(\s*=))</Rule>
+				<Rule color="AttributeValue">=</Rule>
+			</RuleSet>
+		</Span>
+		<Import ruleSet="EntitySet"/>
+	</RuleSet>
+	
+	<RuleSet name="EntitySet">
+		<Rule color="Entity">
+			&amp;
+			[\w\d\#]+
+			;
+		</Rule>
+
+		<Rule color="BrokenEntity">
+			&amp;
+			[\w\d\#]*
+			#missing ;
+		</Rule>
+	</RuleSet>
+</SyntaxDefinition>
\ No newline at end of file
diff --git a/Bloxstrap/UI/Style/Editor-Theme-Light.xshd b/Bloxstrap/UI/Style/Editor-Theme-Light.xshd
new file mode 100644
index 0000000..8f0bdef
--- /dev/null
+++ b/Bloxstrap/UI/Style/Editor-Theme-Light.xshd
@@ -0,0 +1,63 @@
+<SyntaxDefinition name="XML" extensions=".xml;.xsl;.xslt;.xsd;.manifest;.config;.addin;.xshd;.wxs;.wxi;.wxl;.proj;.csproj;.vbproj;.ilproj;.booproj;.build;.xfrm;.targets;.xaml;.xpt;.xft;.map;.wsdl;.disco;.ps1xml;.nuspec" xmlns="http://icsharpcode.net/sharpdevelop/syntaxdefinition/2008">
+	<Color foreground="Green" name="Comment" exampleText="&lt;!-- comment --&gt;" />
+	<Color foreground="Blue" name="CData" exampleText="&lt;![CDATA[data]]&gt;" />
+	<Color foreground="Blue" name="DocType" exampleText="&lt;!DOCTYPE rootElement&gt;" />
+	<Color foreground="Blue" name="XmlDeclaration" exampleText='&lt;?xml version="1.0"?&gt;' />
+	<Color foreground="DarkMagenta" name="XmlTag" exampleText='&lt;tag attribute="value" /&gt;' />
+	<Color foreground="Red" name="AttributeName" exampleText='&lt;tag attribute="value" /&gt;' />
+	<Color foreground="Blue" name="AttributeValue" exampleText='&lt;tag attribute="value" /&gt;' />
+	<Color foreground="Teal" name="Entity" exampleText="index.aspx?a=1&amp;amp;b=2" />
+	<Color foreground="Olive" name="BrokenEntity" exampleText="index.aspx?a=1&amp;b=2" />
+	
+	<RuleSet>
+		<Span color="Comment" multiline="true">
+			<Begin>&lt;!--</Begin>
+			<End>--&gt;</End>
+		</Span>
+		<Span color="CData" multiline="true">
+			<Begin>&lt;!\[CDATA\[</Begin>
+			<End>]]&gt;</End>
+		</Span>
+		<Span color="DocType" multiline="true">
+			<Begin>&lt;!DOCTYPE</Begin>
+			<End>&gt;</End>
+		</Span>
+		<Span color="XmlDeclaration" multiline="true">
+			<Begin>&lt;\?</Begin>
+			<End>\?&gt;</End>
+		</Span>
+		<Span color="XmlTag" multiline="true">
+			<Begin>&lt;</Begin>
+			<End>&gt;</End>
+			<RuleSet>
+				<!-- Treat the position before '<' as end, as that's not a valid character
+				     in attribute names and indicates the user forgot a closing quote. -->
+				<Span color="AttributeValue" multiline="true" ruleSet="EntitySet">
+					<Begin>"</Begin>
+					<End>"|(?=&lt;)</End>
+				</Span>
+				<Span color="AttributeValue" multiline="true" ruleSet="EntitySet">
+					<Begin>'</Begin>
+					<End>'|(?=&lt;)</End>
+				</Span>
+				<Rule color="AttributeName">[\d\w_\-\.]+(?=(\s*=))</Rule>
+				<Rule color="AttributeValue">=</Rule>
+			</RuleSet>
+		</Span>
+		<Import ruleSet="EntitySet"/>
+	</RuleSet>
+	
+	<RuleSet name="EntitySet">
+		<Rule color="Entity">
+			&amp;
+			[\w\d\#]+
+			;
+		</Rule>
+
+		<Rule color="BrokenEntity">
+			&amp;
+			[\w\d\#]*
+			#missing ;
+		</Rule>
+	</RuleSet>
+</SyntaxDefinition>
\ No newline at end of file
diff --git a/Bloxstrap/UI/Style/Light.xaml b/Bloxstrap/UI/Style/Light.xaml
new file mode 100644
index 0000000..fcc308d
--- /dev/null
+++ b/Bloxstrap/UI/Style/Light.xaml
@@ -0,0 +1,5 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <SolidColorBrush x:Key="NewTextEditorBackground" Color="White" />
+    <SolidColorBrush x:Key="NewTextEditorForeground" Color="Black" />
+    <SolidColorBrush x:Key="NewTextEditorLink" Color="Blue" />
+</ResourceDictionary>
\ No newline at end of file