App.xaml

<Application x:Class="BasicCRUDTool.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:BasicCRUDTool"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Resources/Styles/Colours.xaml"/>
                <ResourceDictionary Source="Resources/Styles/Fonts.xaml"/>
                <ResourceDictionary Source="Resources/Styles/Buttons.xaml"/>
                <ResourceDictionary Source="Resources/Styles/Texts.xaml"/>
                <ResourceDictionary Source="Resources/Styles/Windows.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>