Why will some text fade in WPF but some will Not - wpf

Question

I am creating a WPF app in visual studio using c#. I am trying to make text fade from one color to another. Some of the text will change color but some just stays one singular color. The code appears to be exactly the same so I do not know what I am doing wrong.
// This is the working code
UserControl x:Class="MiniBiotronWPF2.Home"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:MiniBiotronWPF2"
mc:Ignorable="d"
d:DesignHeight="510" d:DesignWidth="650">
<Grid>
<TextBlock
x:Name="MyChangingColorText"
Margin="41,123,10,261" FontSize="48" FontWeight="Bold" Text="Welcome to Mini Biotron">
<TextBlock.Foreground>
<SolidColorBrush x:Name="MySolidColorBrush" Color="White"/>
</TextBlock.Foreground>
<TextBlock.Triggers>
<EventTrigger RoutedEvent="TextBlock.Loaded">
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Storyboard.TargetName="MySolidColorBrush"
Storyboard.TargetProperty="Color"
From="#FF383535" To="White" Duration="0:0:3"
AutoReverse="false" RepeatBehavior="0:0:3" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</TextBlock.Triggers>
</TextBlock>
<TextBlock
x:Name="MyChangingColorText1"
Margin="188,220,156,168" FontSize="48" FontWeight="Bold" Text="Beta Edition">
<TextBlock.Foreground>
<SolidColorBrush x:Name="MySolidColorBrush1" Color="White"/>
</TextBlock.Foreground>
<TextBlock.Triggers>
<EventTrigger RoutedEvent="TextBlock.Loaded">
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Storyboard.TargetName="MySolidColorBrush1"
Storyboard.TargetProperty="Color"
From="#FF383535" To="White" Duration="0:0:3"
AutoReverse="false" RepeatBehavior="0:0:3" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</TextBlock.Triggers>
</TextBlock>
//This is the rest of the program which does not fade
<TextBlock
x:Name="MyChangingColorText2"
Margin="200,385,255,0" FontSize="16" FontWeight="Bold" Text=" Created by Lane Whitten ">
<TextBlock.Foreground>
<SolidColorBrush x:Name="MySolidColorBrush2" Color="White"/>
</TextBlock.Foreground>
<TextBlock.Triggers>
<EventTrigger RoutedEvent="TextBlock.Loaded">
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Storyboard.TargetName="MySolidColorBrush1"
Storyboard.TargetProperty="Color"
From="#FF383535" To="White" Duration="0:0:3"
AutoReverse="false" RepeatBehavior="0:0:3" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</TextBlock.Triggers>
</TextBlock>
<TextBlock
x:Name="MyChangingColorText3"
Margin="200,432,25,0" FontSize="12" FontWeight="Bold" Text=" Copyright © 2018 UW BIOTRON">
<TextBlock.Foreground>
<SolidColorBrush x:Name="MySolidColorBrush3" Color="White"/>
</TextBlock.Foreground>
<TextBlock.Triggers>
<EventTrigger RoutedEvent="TextBlock.Loaded">
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Storyboard.TargetName="MySolidColorBrush1"
Storyboard.TargetProperty="Color"
From="#FF383535" To="White" Duration="0:0:3"
AutoReverse="false" RepeatBehavior="0:0:3" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</TextBlock.Triggers>
</TextBlock>
<TextBlock
x:Name="MyChangingColorText4"
Margin="71,409,25,0" FontSize="12" FontWeight="Bold" Text=" For questions, concerns or to request new features contact: lanewhitten14#gmail.com ">
<TextBlock.Foreground>
<SolidColorBrush x:Name="MySolidColorBrush4" Color="White"/>
</TextBlock.Foreground>
<TextBlock.Triggers>
<EventTrigger RoutedEvent="TextBlock.Loaded">
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Storyboard.TargetName="MySolidColorBrush"
Storyboard.TargetProperty="Color"
From="#FF383535" To="White" Duration="0:0:3"
AutoReverse="false" RepeatBehavior="0:0:3" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</TextBlock.Triggers>
</TextBlock>
</Grid>
</UserControl>

Answer 1

Your non-working TextBlock are targeting to SolidColorBrush1 which should be MySolidColorBrush2,MySolidColorBrush3....
Instead define a Style as Resource:
<Window.Resources>
<SolidColorBrush x:Key="TextBrush">Black</SolidColorBrush>
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="{StaticResource TextBrush}"/>
<Style.Triggers>
<EventTrigger RoutedEvent="TextBlock.Loaded">
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Storyboard.TargetProperty="(TextBlock.Foreground).(SolidColorBrush.Color)"
From="#FF383535" To="White" Duration="0:0:3"
AutoReverse="false" RepeatBehavior="Forever" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Style.Triggers>
</Style>
</Window.Resources>
Then just define Textblock in the same window:
<TextBlock Text="Text1"/>

Answer 2

In your first example that doesn't work, take a look at
Storyboard.TargetName="MySolidColorBrush1"
This Textblock element can't find MySolidColorBrush1 so it doesn't work correctly. You should put brushes in your UserControl.Resources so that every element in this UserControl can find the Brush resource.