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

What version of WPF are you using? I tried in both 3.5 and 4.0, and Fill="#FF000000" should work fine in a in the XAML. There is another syntax, however, if it doesn't. Here's a 3.5 XAML that I tested with two different ways. Better yet would be to use a resource.

<Window x:Class="WpfApplication2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Rectangle Height="100" HorizontalAlignment="Left" Margin="100,12,0,0" Name="rectangle1" Stroke="Black" VerticalAlignment="Top" Width="200" Fill="#FF00AE00" />
    <Rectangle Height="100" HorizontalAlignment="Left" Margin="100,132,0,0" Name="rectangle2" Stroke="Black" VerticalAlignment="Top" Width="200" >
        <Rectangle.Fill>
            <SolidColorBrush Color="#FF00AE00" />
        </Rectangle.Fill>
    </Rectangle>
</Grid>