App.xaml

<Application x:Class="BeQuietApplication.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:BeQuietApplication"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <!-- Contains all of the colours and brushes for a theme -->
                <ResourceDictionary Source="Themes/ColourDictionaries/DeepDark.xaml"/>
                <!-- Contains most of the control-specific brushes which reference -->
                <!-- the above theme. I aim for this to contain ALL brushes, not most  -->
                <ResourceDictionary Source="Themes/ControlColours.xaml"/>
                <!-- Contains all of the control styles (Button, ListBox, etc) -->
                <ResourceDictionary Source="Themes/Controls.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>