Наприклад так:
<Window x:Class="Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="TryAnimationOverride" Height="300" Width="300"
>
<Window.Resources>
<Style x:Key="ButtonStyle" TargetType="{x:Type Button}">
<Setter Property="Button.Background" Value="Black"/>
<Setter Property="Foreground" Value="Red"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border
Width="{TemplateBinding FrameworkElement.Width}"
Height="{TemplateBinding FrameworkElement.Height}"
Background="{TemplateBinding Control.Background}"
>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" Content="{TemplateBinding ContentControl.Content}" />
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Button.IsMouseOver" Value="true">
<Setter Property="Button.Background" Value="Green" />
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources> <Button Content="123" Width="100" Height="75" Style="{StaticResource ButtonStyle}" Click="ButtonClick"/>
</Window>
Тобто повністю зробіть свій ControlTemplate
