WPF

<XmlDataProvider x:Key="MoreColors" XPath="/colors">
    <x:XData>
        <colors xmlns="" >
            <color name="pink"/>
            <color name="white"/>
            <color name="black"/>
            <color name="cyan"/>
            <color name="gray"/>
            <color name="magenta"/>
        </colors>
    </x:XData>
</XmlDataProvider>

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">

    <StackPanel Orientation="Vertical">
        <TextBox Name="txtVersion" Text="????"></TextBox>
        <Button Content="Version 1" Click="Version1_Click"></Button>
        <Button Content="Version 2" Click="Version2_Click"></Button>
    </StackPanel>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1
{
    public partial class MainWindow : Window, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        License license1;
        License license2;

        public MainWindow()
        {
            InitializeComponent();

            license1 = new License("Version 1");
            license2 = new License("Version 2");

            License.Current = license1;

            this.DataContext = this;
            this.PropertyChanged += new PropertyChangedEventHandler(MainWindow_PropertyChanged);
        }

        void MainWindow_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {

        }

        private void Version1_Click(object sender, RoutedEventArgs e)
        {
            License.Current = license1;
            PropertyChanged(this, new PropertyChangedEventArgs("Version"));
        }

        private void Version2_Click(object sender, RoutedEventArgs e)
        {
            License.Current = license2;
            PropertyChanged(this, new PropertyChangedEventArgs("Version"));
        }
    }

    class License
    {
        static License current;
        string version;

        public License(string version)
        {
            this.version = version;
        }

        public static License Current
        {
            get { return current; }
            set { current = value; }
        }

        public string Version
        {
            get { return version; }
        }
    }
}

<Style x:Key="ComboStyle" TargetType="{x:Type ComboBox}">
     <Setter Property="Template">
         <Setter.Value>
             <ControlTemplate TargetType="{x:Type ComboBox}">
                 <Border Name="bd" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding Background}" Padding="2">
                     <ContentPresenter />
                 </Border>
                 <ControlTemplate.Triggers>
                     <Trigger Property="IsMouseOver" Value="True">
                         <Setter TargetName="bd" Property="Background" Value="#F7F7F7" />
                     </Trigger>
                 </ControlTemplate.Triggers>
             </ControlTemplate>
         </Setter.Value>
     </Setter>
 </Style>