How to convert color code into media.brush? [duplicate]

I have a rectangle that i want to fill with a color. When i write Fill = "#FFFFFF90" it shows me an error:

Cannot implicitly convert type 'string' to 'System.Windows.Media.Brush

Please give me some advice.

You could use the same mechanism the XAML reading system uses: Type converters

var converter = new System.Windows.Media.BrushConverter();
var brush = (Brush)converter.ConvertFromString("#FFFFFF90");
Fill = brush;

In code, you need to explicitly create a Brush instance:

Fill = new SolidColorBrush(Color.FromArgb(0xff, 0xff, 0x90))

For WinRT (Windows Store App)

using Windows.UI;
using Windows.UI.Xaml.Media;

    public static Brush ColorToBrush(string color) // color = "#E7E44D"
    {
        color = color.Replace("#", "");
        if (color.Length == 6)
        {
            return new SolidColorBrush(ColorHelper.FromArgb(255,
                byte.Parse(color.Substring(0, 2), System.Globalization.NumberStyles.HexNumber),
                byte.Parse(color.Substring(2, 2), System.Globalization.NumberStyles.HexNumber),
                byte.Parse(color.Substring(4, 2), System.Globalization.NumberStyles.HexNumber)));
        }
        else
        {
            return null;
        }
    }