wpf将椭圆gradientstop颜色绑定到ivalueconverter

Question

我已将椭圆绑定到复选框和iValueConverter（此作品 ...填充（见下文））。

 <Ellipse Name="ellLeftRoleEnabled" 
                 Fill="{Binding IsChecked, ElementName=btnRollLeftEnabled, Converter={StaticResource myColorConverter}}" 
                 Height="80" Canvas.Left="355" Stroke="#FF0C703E" Canvas.Top="440" Width="80"/>

但是现在，我如何将它用于LinearGradientBrush / GradientStop？

<Ellipse Name="ellLeftRoleMoving" Height="100" Canvas.Left="345" Stroke="Black" Canvas.Top="535" Width="100">
            <Ellipse.Fill>
                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                    <GradientStop Color="{?????} Offset="0"/>
                    <GradientStop Color="White" Offset="1"/>
                </LinearGradientBrush>
            </Ellipse.Fill>
        </Ellipse>

请帮忙。谢谢。