Revert "Break the API"

This reverts commit f043f6b1617c85706c7c33741024a09b5b8c7d89.

src/Avalonia.Controls.ColorPicker/ColorChangedEventArgs.cs

@@ -24,14 +24,14 @@ namespace Avalonia.Controls
         /// <param name="newColor">The new/updated color that triggered the change event.</param>
         public ColorChangedEventArgs(Color oldColor, Color newColor)
         {
-            //OldColor = oldColor;
+            OldColor = oldColor;
             NewColor = newColor;
         }
 
         /// <summary>
         /// Gets the old/original color from before the change event.
         /// </summary>
-        //public Color OldColor { get; private set; }
+        public Color OldColor { get; private set; }
 
         /// <summary>
         /// Gets the new/updated color that triggered the change event.

src/Avalonia.Controls.ColorPicker/HsvComponent.cs

@@ -18,7 +18,7 @@ namespace Avalonia.Controls
         /// <remarks>
         /// Also see: <see cref="HsvColor.A"/>
         /// </remarks>
-        // Alpha = 0,
+        Alpha = 0,
 
         /// <summary>
         /// The Hue component.