TextBlock.Foreground (Propiedad)

<TextBlock 
  Name="textBlock"

  Background="AntiqueWhite" 
  Foreground="Navy" 

  FontFamily="Century Gothic"
  FontSize="12"
  FontStretch="UltraExpanded"
  FontStyle="Italic"
  FontWeight="UltraBold"

  LineHeight="Auto"
  Padding="5,10,5,10"
  TextAlignment="Center"
  TextWrapping="Wrap"

  Typography.NumeralStyle="OldStyle"
  Typography.SlashedZero="True"
>
  <Run Background="LightGreen">Text run 1.</Run>
  <LineBreak/><Run Background="LightBlue">Text run 2.</Run>
  <LineBreak/><Run Background="LightYellow">Text run 3.</Run>
</TextBlock>

TextBlock textBlock = new TextBlock(new Run("A bit of text content..."));

textBlock.Background              = Brushes.AntiqueWhite;
textBlock.Foreground              = Brushes.Navy;

textBlock.FontFamily              = new FontFamily("Century Gothic");
textBlock.FontSize                = 12;
textBlock.FontStretch             = FontStretches.UltraExpanded;
textBlock.FontStyle               = FontStyles.Italic;
textBlock.FontWeight              = FontWeights.UltraBold;

textBlock.LineHeight              = Double.NaN;
textBlock.Padding                 = new Thickness(5, 10, 5, 10);
textBlock.TextAlignment           = TextAlignment.Center;
textBlock.TextWrapping            = TextWrapping.Wrap;

textBlock.Typography.NumeralStyle = FontNumeralStyle.OldStyle;
textBlock.Typography.SlashedZero  = true;