gg/App.xaml

<Application x:Class="RR2.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:RR2"
             StartupUri="UI\Views\MainWnd.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>

                <ResourceDictionary Source="UI/Styles/Palette.xaml"/>
                <ResourceDictionary Source="UI/Styles/MainStyle.xaml"/>

            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>