MainWindow.xaml

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:CustomColorSchemes" 
        xmlns:dxda="http://schemas.devexpress.com/winfx/2008/xaml/dataaccess" 
        xmlns:dxrud="http://schemas.devexpress.com/winfx/2008/xaml/reports/userdesigner"
        xmlns:dxrudw="http://schemas.devexpress.com/winfx/2008/xaml/reports/userdesigner/wizard"
        x:Class="CustomColorSchemes.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <dxrud:ReportDesigner>
            <dxrud:ReportDesigner.ServicesRegistry>
                <!-- Register the wizard customization service.-->
                <dxda:TypeEntry ServiceType="{x:Type dxrudw:IWizardCustomizationService}" 
                                ConcreteType="{x:Type local:WizardCustomization}" />
            </dxrud:ReportDesigner.ServicesRegistry>
        </dxrud:ReportDesigner>
    </Grid>
</Window>