Color Binding Not Working for Data Templates in Win8 App - xaml

Question

I'm currently trying to add some sort of a Color Theme feature to a Win8 App I'm working at... I've though of making a binding from a vm, and everything works fine for static UI elements. But, I'm adding some notes (my model) into a DB, and they also appear on the screen into a GridView.
But in the declared DataTemplate for the GridView ItemTemplate, the Color Binding will not work at all...
My template looks like this :
<Grid Grid.Row="3" HorizontalAlignment="Left" Width="200" Height="200">
<Grid.RowDefinitions>
<RowDefinition Height="100"/>
<RowDefinition Height="60"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Border Grid.Row="0" Background="Lavender" Opacity="50"/>
<ScrollViewer Grid.Row="0">
<TextBlock Grid.Row="0" Text="{Binding Content}" Foreground="DodgerBlue" />
</ScrollViewer>
<Border Grid.Row="1" Background="DodgerBlue" Opacity="70"/>
<ScrollViewer Grid.Row="1">
<TextBlock Grid.Row="1" Text="{Binding Subject}" Foreground="LightBlue" />
</ScrollViewer>
<Border Grid.Row="2" Background="DodgerBlue" Opacity="70"/>
<TextBlock Grid.Row="2" Text="{Binding Importance}" Foreground="Black" FontSize="{StaticResource ComboBoxArrowThemeFontSize}" />
</Grid>
What I tried was simply instead of Foreground="DodgerBlue" to Foreground="{Binding ColorTheme}" but it had no effect, the SolidColorBrush was not acquired from vm....
Is there any workaround for this?
Many thanks in advance.

Answer 1

Altough I didn't really find out the actual explanation on why the below works (and I hope someone more experience, maybe could explain me), this post, seemed to have worked for me.
Not very sure, but was a matter of DataContext, so instead of trying a binding like this : Foreground={Binding ColorTheme}, I changed to this : Foreground={Binding DataContext.ColorTheme, ElementName=MyGridViewName}".

Answer 2

Color binding (or better: brush binding) should work just fine - in GridView.ItemTemplate scenario and elsewhere.
You haven't given enough info to pinpoint why it doesn't work in your case, but here is a small sample I've just tried out:
GridView to put in your page:
<GridView Width="600" Height="200" ItemsSource="{Binding GridItems}"
x:Name="GridViewName">
<GridView.ItemTemplate>
<DataTemplate>
<TextBlock Width="50" Height="50"
Foreground="{Binding Color}" Text="{Binding Text}" />
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
View model class bound as DataContext for your page:
public class ViewModel
{
public ViewModel()
{
GridItems = new List<GridItem>
{
new GridItem {Text = "First", Color = new SolidColorBrush(Colors.White)},
new GridItem {Text = "Second", Color = new SolidColorBrush(Colors.Yellow)},
new GridItem {Text = "Third", Color = new SolidColorBrush(Colors.Green)},
new GridItem {Text = "Fourth", Color = new SolidColorBrush(Colors.Red)},
};
}
}
GridItem class:
public class GridItem
{
public string Text { get; set; }
public Brush Color { get; set; }
}
The result:
EDIT:
I need to point out that inside data template DataContext is set to the current item of the bound collection (GridItems in my case) not to the page DataContext (ViewModel in my case).
This means that by setting {Binding Color} to a control property you're binding to GridItem.Color not to ViewModel.Color. To make the latter work you first need to access the parent DataContext using the ElementName syntax as you already suggested in your own answer: {Binding DataContext.ColorTheme, ElementName=GridViewName} - this binds to a named element on the page and allows you to access its properties, DataContext being ViewModel in this case.