PixiEditor/PixiEditorDotNetCore3/Styles/ThemeStyle.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:local="clr-namespace:PixiEditor.Styles">

    <Style TargetType="Button" x:Key="DarkRoundButton">
        <Setter Property="Background" Value="#404040"/>
        <Setter Property="Foreground" Value="White"/>
        <Setter Property="FontSize" Value="22"/>
        <Setter Property="SnapsToDevicePixels" Value="True"/>

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <Border CornerRadius="4" Background="{TemplateBinding Background}">
                        <ContentPresenter Content="{TemplateBinding Content}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                    </Border>

                    <ControlTemplate.Triggers>
                        <Trigger Property="IsEnabled" Value="False">
                            <Setter Property="Background" Value="#404040"/>
                            <Setter Property="Foreground" Value="White"/>
                            <Setter Property="Cursor" Value="Arrow"/>
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Background" Value="#FF515151"/>
                            <Setter Property="Foreground" Value="White"/>
                            <Setter Property="Cursor" Value="Hand"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="True">
                            <Setter Property="Background" Value="#505050"/>
                            <Setter Property="Foreground" Value="White"/>
                        </Trigger>
                    </ControlTemplate.Triggers>

                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>


    <Style TargetType="TextBox" x:Key="DarkTextBoxStyle">
        <Setter Property="Background" Value="#202020"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="BorderBrush" Value="#404040"/>
        <Setter Property="Foreground" Value="Snow"/>
    </Style>

    <Style TargetType="Button" x:Key="ToolButtonStyle">
        <Setter Property="Height" Value="52"/>
        <Setter Property="Width" Value="52"/>
        <Setter Property="VerticalAlignment" Value="Top"/>
        <Setter Property="HorizontalAlignment" Value="Center"/>
        <Setter Property="Margin" Value="0,10,0,0"/>
    </Style>
</ResourceDictionary>