ColorBox

.cs

using System;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;
using TDMS3DControl.Commands;
using TDMS3DControl.Models;
using TDMS3DControl.Views;

namespace TDMS3DControl.ViewModels
{

    class ColorBoxViewModel : BaseViewModel
    {
        public int ClickResult { get; set; }

        private SolidColorBrush elementColor;
        public SolidColorBrush ElementColor { get => elementColor; set { elementColor = value; OnPropertyChanged(); } }

        public System.Drawing.Color StatusColor { get; set; } = System.Drawing.Color.Empty;

        public ICommand CheckColor { get; set; }
        public ICommand SetColor { get; set; }
        public ICommand SetBaseColor { get; set; }

        private readonly ColorBox Box;

        public ColorBoxViewModel(ColorBox box)
        {
            Box = box;
            CheckColor = new Command(CheckColorMethod);
            SetColor = new Command(SetColorMethod);
            SetBaseColor = new Command(SetBaseColorMethod);
        }

        private void CheckColorMethod(object obj)
        {
            ElementColor = (SolidColorBrush)obj;
        }
        public System.Drawing.Color ToDrawingColor(SolidColorBrush mediaColor)
        {
            if (mediaColor == null) return System.Drawing.Color.Empty;
            if (mediaColor.Color.R.ToString() == "255")
                return System.Drawing.Color.Red;
            else if(mediaColor.Color.G.ToString() == "128")
                return System.Drawing.Color.Green;
            else
                return System.Drawing.Color.Blue;
        }

        private void SetBaseColorMethod(object obj)
        {
            ClickResult = 2;
            Box.Close();
        }

        private void SetColorMethod(object obj)
        {
            ClickResult = 1;

            StatusColor = ToDrawingColor(ElementColor);

            Box.Close();
        }
    }
}

.xaml

<Window x:Class="TDMS3DControl.Views.ColorBox"
        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:TDMS3DControl.Views"
        xmlns:TestXBim="clr-namespace:TDMS3DControl.ViewModels" 
        xmlns:md="http://materialdesigninxaml.net/winfx/xaml/themes"
        mc:Ignorable="d"
        Title="ColorBox" Height="250" Width="250">

    <Window.Resources>
        <Style TargetType="{x:Type RadioButton}" >
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type RadioButton}">
                        <Border>
                            <Rectangle x:Name="Rectangle" Width="30" Height="50" Fill="{TemplateBinding Background}" />
                        </Border>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsChecked" Value="true">
                                <Setter TargetName="Rectangle" Property="Width" Value="40"/>
                                <Setter TargetName="Rectangle" Property="Height" Value="60"/>
                            </Trigger>
                            <Trigger Property="IsMouseOver" Value="true">
                                <Setter TargetName="Rectangle" Property="Width" Value="40"/>
                                <Setter TargetName="Rectangle" Property="Height" Value="60"/>
                                <Setter TargetName="Rectangle" Property="Cursor" Value="Hand"/>
                            </Trigger>
                            <Trigger Property="IsPressed" Value="true">
                                <Setter TargetName="Rectangle" Property="Width" Value="35"/>
                                <Setter TargetName="Rectangle" Property="Height" Value="55"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Resources>

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="5*"/>
            <RowDefinition Height="1*" />
            <RowDefinition Height="1*"/>
        </Grid.RowDefinitions>

        <Grid Grid.Row="0" Grid.IsSharedSizeScope="True">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="1*"/>
                <ColumnDefinition Width="1*"/>
                <ColumnDefinition Width="1*"/>
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="103*"/>
                <RowDefinition Height="32*"/>
            </Grid.RowDefinitions>

            <RadioButton Width="40" Grid.Column="0" Background="Red" VerticalAlignment="Center"   GroupName="Colors"  
                         Command="{Binding CheckColor}" 
                         CommandParameter="{Binding RelativeSource={RelativeSource Self}, Path=Background}"  />
            <RadioButton Width="40" Grid.Column="1" Background="Green" VerticalAlignment="Center"  GroupName="Colors" 
                         Command="{Binding CheckColor}" 
                         CommandParameter="{Binding RelativeSource={RelativeSource Self}, Path=Background}"   />
            <RadioButton Width="40" Grid.Column="2" Background="Blue" VerticalAlignment="Center"  GroupName="Colors" 
                         Command="{Binding CheckColor}" 
                         CommandParameter="{Binding RelativeSource={RelativeSource Self}, Path=Background}"   />
        </Grid>
        <Button Grid.Row="1" Background="AliceBlue" Content="Установить новый цвет" Margin="5" Command="{Binding SetColor}" />
        <Button Grid.Row="2" Background="AliceBlue" Content="Установить базовый цвет" Margin="5" Command="{Binding SetBaseColor}" />
    </Grid>
</Window>