using System.ComponentModel;
using System.Windows.Media;

namespace ClientUI.Samples.Models
{
    public class Product : INotifyPropertyChanged
    {
        private string _name;
        private string _category;
        private SolidColorBrush _categoryBrush;
      
        public string Name
        {
            get { return this._name; }
            set
            {
                if (this._name!= value)
                {
                    this._name= value;
                    this.OnPropertyChanged("Name");
                }
            }
        }

        public string Category
        {
            get { return this._category; }
            set
            {
                if (this._category != value)
                {
                    this._category = value;

                    switch (value)
                    {
                        case "Red":
                            this.CategoryBrush = new SolidColorBrush(Color.FromArgb(255, 255, 0, 0));
                            break;
                        case "Green":
                            this.CategoryBrush = new SolidColorBrush(Color.FromArgb(255, 0, 255, 0));
                            break;
                        case "Blue":
                            this.CategoryBrush = new SolidColorBrush(Color.FromArgb(255, 0, 0, 255));
                            break;
                        default:
                            this.CategoryBrush = new SolidColorBrush(Color.FromArgb(0, 0, 0, 0));
                            break;
                    }
                    this.OnPropertyChanged("Category");
                }
            }
        }

        public SolidColorBrush CategoryBrush
        {
            get { return this._categoryBrush; }
            set
            {
                if (this._categoryBrush != value)
                {
                    this._categoryBrush = value;
                    this.OnPropertyChanged("CategoryBrush");
                }
            }
        }

        protected void OnPropertyChanged(string propertyName)
        {
            if (this.PropertyChanged != null)
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }
}

using System.Collections.ObjectModel;
using System.ComponentModel;
using ClientUI.Samples.Models;

namespace ClientUI.Samples.ViewModels
{
    public class MainPageViewModel : INotifyPropertyChanged
    {
        public MainPageViewModel()
        {
            this.Products = new ObservableCollection<Product>();
            this.Products.Add(new Product() { Category = "Red", Name = "Product 1" });
            this.Products.Add(new Product() { Category = "Red", Name = "Product 2" });
            this.Products.Add(new Product() { Category = "Blue", Name = "Product 3" });
            this.Products.Add(new Product() { Category = "Blue", Name = "Product 4" });
            this.Products.Add(new Product() { Category = "Green", Name = "Product 5" });            
        }

        private ObservableCollection<Product> _products;

        public ObservableCollection<Product> Products
        {
            get { return this._products; }
            set
            {
                if (this._products != value)
                {
                    this._products = value;
                    this.OnPropertyChanged("Products");
                }
            }
        }

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }
}