Forum description here: https://www.noesisengine.com/forums/viewtopic.php?p=11423

XamlToy ready example of issue (databinding to blue fails):

<Grid
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

<ContentControl>
<ContentControl.Content>
<Color>#ff0000ff</Color>
</ContentControl.Content>
<ContentControl.ContentTemplate>
<DataTemplate>
<Grid>
<Rectangle Name="SomeRect" Width="200" Height="200" Fill="Pink">
<Rectangle.Triggers>
<EventTrigger RoutedEvent="Rectangle.Loaded">
<EventTrigger.Actions>
<BeginStoryboard>
<Storyboard>
<ColorAnimation
Duration="0:0:5"
From="Green"
To="{Binding}"
AutoReverse="True" RepeatBehavior="Forever"
Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)"
Storyboard.TargetName="SomeRect">
</ColorAnimation>
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
</Rectangle.Triggers>
</Rectangle>
</Grid>
</DataTemplate>
</ContentControl.ContentTemplate>
</ContentControl>
</Grid>