Code WPF Pixel Paint

if (((Button)sender).Background.ToString() == "#FFDDDDDD")
{
  ((Button)sender).Background = Brushes.Red;
}
else if (((Button)sender).Background == Brushes.Red)
{
  ((Button)sender).Background = Brushes.GreenYellow;
}
else if (((Button)sender).Background == Brushes.GreenYellow)
{
  ((Button)sender).Background = Brushes.Orange;
}
else if (((Button)sender).Background == Brushes.Orange)
{
  ((Button)sender).Background = Brushes.SteelBlue;
}
else {
  ((Button)sender).Background = (Brush)(new BrushConverter().ConvertFrom("#FFDDDDDD"));
}
 
<Window x:Class="PixelPaint.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:PixelPaint"
        mc:Ignorable="d"
        Title="Pixel Pain" Height="1000" Width="1000">
  <Grid>
    <Grid.RowDefinitions>
      <RowDefinition />
      <RowDefinition />
      <RowDefinition />
      <RowDefinition />
      <RowDefinition />
      <RowDefinition />
      <RowDefinition />
      <RowDefinition />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
    </Grid.ColumnDefinitions>

    <Button Grid.Row="0" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="0" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="0" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="0" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="0" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="0" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="0" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="0" Grid.Column="7" Click="Button_Click" />

    <Button Grid.Row="1" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="1" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="1" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="1" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="1" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="1" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="1" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="1" Grid.Column="7" Click="Button_Click" />

    <Button Grid.Row="2" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="2" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="2" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="2" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="2" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="2" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="2" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="2" Grid.Column="7" Click="Button_Click" />

    <Button Grid.Row="3" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="3" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="3" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="3" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="3" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="3" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="3" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="3" Grid.Column="7" Click="Button_Click" />

    <Button Grid.Row="4" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="4" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="4" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="4" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="4" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="4" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="4" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="4" Grid.Column="7" Click="Button_Click" />

    <Button Grid.Row="5" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="5" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="5" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="5" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="5" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="5" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="5" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="5" Grid.Column="7" Click="Button_Click" />

    <Button Grid.Row="6" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="6" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="6" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="6" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="6" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="6" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="6" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="6" Grid.Column="7" Click="Button_Click" />

    <Button Grid.Row="7" Grid.Column="0" Click="Button_Click" />
    <Button Grid.Row="7" Grid.Column="1" Click="Button_Click" />
    <Button Grid.Row="7" Grid.Column="2" Click="Button_Click" />
    <Button Grid.Row="7" Grid.Column="3" Click="Button_Click" />
    <Button Grid.Row="7" Grid.Column="4" Click="Button_Click" />
    <Button Grid.Row="7" Grid.Column="5" Click="Button_Click" />
    <Button Grid.Row="7" Grid.Column="6" Click="Button_Click" />
    <Button Grid.Row="7" Grid.Column="7" Click="Button_Click" />
  </Grid>
</Window>