diff --git a/PacticeSolution/BindingValidationRuleSample/Converter/ButtonTextBrush.cs b/PacticeSolution/BindingValidationRuleSample/Converter/ButtonTextBrush.cs
new file mode 100644
index 0000000..a8d6824
--- /dev/null
+++ b/PacticeSolution/BindingValidationRuleSample/Converter/ButtonTextBrush.cs
@@ -0,0 +1,43 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Data;
+using System.Windows.Media;
+
+namespace BindingValidationRuleSample.Converter
+{
+    [ValueConversion(typeof(int), typeof(Brush))]
+    internal class ButtonTextBrush : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (targetType != typeof(Brush))
+                return null;
+
+            if (value == null)
+                return null;
+
+            int age = int.Parse(value.ToString());
+            return ValueColor(age);
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return null;
+        }
+
+        private Brush ValueColor(int age)
+        {
+            if (age >= 10 && age < 20)
+                return Brushes.HotPink;
+
+            if (age >= 20 && age < 30)
+                return Brushes.DarkOliveGreen;
+
+            return Brushes.MediumPurple;
+        }
+    }
+}
diff --git a/PacticeSolution/BindingValidationRuleSample/MainWindow.xaml b/PacticeSolution/BindingValidationRuleSample/MainWindow.xaml
index 9e6e75a..fe97c39 100644
--- a/PacticeSolution/BindingValidationRuleSample/MainWindow.xaml
+++ b/PacticeSolution/BindingValidationRuleSample/MainWindow.xaml
@@ -6,11 +6,15 @@
         xmlns:local="clr-namespace:BindingValidationRuleSample"
         xmlns:model="clr-namespace:BindingValidationRuleSample.Model"
         xmlns:validation="clr-namespace:BindingValidationRuleSample.Validation"
+        xmlns:converter="clr-namespace:BindingValidationRuleSample.Converter"
         mc:Ignorable="d"
         Title="MainWindow" Height="200" Width="300">
     <Window.DataContext>
         <model:Student/>
     </Window.DataContext>
+    <Window.Resources>
+        <converter:ButtonTextBrush x:Key="cvtAgeToBrush"/>
+    </Window.Resources>
 
     <Grid>
         <Grid.ColumnDefinitions>
@@ -45,7 +49,8 @@
                 </Binding>
             </TextBox.Text>
         </TextBox>
-        <TextBox Grid.Column="1" Grid.Row="2" Margin="5" Foreground="Blue"
+        <TextBox Grid.Column="1" Grid.Row="2" Margin="5"
+                 Foreground="{Binding Path=Age, Mode=TwoWay, Converter={StaticResource cvtAgeToBrush}}"
                  Text="{Binding PhoneNumber, Mode=TwoWay}"/>
 
         <Grid Grid.Column="0" Grid.Row="4" Grid.ColumnSpan="2" Height="30">
diff --git a/PacticeSolution/PacticeSolution.sln b/PacticeSolution/PacticeSolution.sln
index 8e24b32..2fc5041 100644
--- a/PacticeSolution/PacticeSolution.sln
+++ b/PacticeSolution/PacticeSolution.sln
@@ -47,13 +47,13 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LabelTextBlockTextBoxSample
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ListBoxBindingSample", "ListBoxBindingSample\ListBoxBindingSample.csproj", "{71B7E9C4-C73B-4701-B702-A91AB5630580}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "KeyboardInputSample", "KeyboardInputSample\KeyboardInputSample.csproj", "{B6A7E0D5-A2C7-4083-A060-1672E6FBDC82}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "KeyboardInputSample", "KeyboardInputSample\KeyboardInputSample.csproj", "{B6A7E0D5-A2C7-4083-A060-1672E6FBDC82}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TabControlSample", "TabControlSample\TabControlSample.csproj", "{7A148D37-36D1-43B5-A133-B02CE5CB743F}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TabControlSample", "TabControlSample\TabControlSample.csproj", "{7A148D37-36D1-43B5-A133-B02CE5CB743F}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProgressBarSample", "ProgressBarSample\ProgressBarSample.csproj", "{EB304FB7-67EA-467E-9BE4-E55187415CAB}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ProgressBarSample", "ProgressBarSample\ProgressBarSample.csproj", "{EB304FB7-67EA-467E-9BE4-E55187415CAB}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BindingValidationRuleSample", "BindingValidationRuleSample\BindingValidationRuleSample.csproj", "{B328C31A-8C85-4A48-A12F-26E11C37A15C}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BindingValidationRuleSample", "BindingValidationRuleSample\BindingValidationRuleSample.csproj", "{B328C31A-8C85-4A48-A12F-26E11C37A15C}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution