This ValueConverter expects a string of either "Heads" or "Tails" and returns Green or Red respectively or yellow as a default or unknown value. I use it in a Windows Store Application, "Decisive" to color the text result of a coin toss. I've been using a long weekend as a sprint to focus on learning VS2012 and blend design tools. Blend made it …

HeadsOrTailsToColorConverter.cs

using System;
using Windows.UI;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Media;

namespace Decisive.Common
{
    public sealed class HeadsOrTailsToColorConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, string language)
        {
                switch (value as string)
                {
                    case "Heads":
                        return new SolidColorBrush(Colors.Green);
                    case "Tails":
                        return new SolidColorBrush(Colors.Red);
                    default:
                        return new SolidColorBrush(Colors.Yellow);
                }
            }

        public object ConvertBack(object value, Type targetType, object parameter, string language)
        {
            throw new NotImplementedException();
        }
    }
}

HeadsOrTailsToColorConverterExampleView.xaml

    <Page.Resources>
        <uncommon:HeadsOrTailsToColorConverter x:Key="TextToColor" />
    </Page.Resources>
    
            <TextBlock x:Name="textBlockYeaNoAnswer"
                       Grid.Column="0"
                       Grid.Row="1"
                       HorizontalAlignment="Center"
                       VerticalAlignment="Center"
                       Text="{Binding YeaNoAnswer}"
                       FontSize="56"
                       Foreground="{Binding Text, Converter={StaticResource TextToColor}, RelativeSource={RelativeSource Mode=Self}}"
                       FontWeight="Bold" />