InTemplateOf should only affect later selectors.

So return a copy of the match.

Perspex/Styling/Match.cs

@@ -20,6 +20,14 @@ namespace Perspex.Styling
             this.Observables = new List<IObservable<bool>>();
         }
 
+        public Match(Match source)
+        {
+            this.Control = source.Control;
+            this.InTemplate = source.InTemplate;
+            this.Observables = source.Observables;
+            this.SelectorString = SelectorString;
+        }
+
         public IStyleable Control
         {
             get;

Perspex/Styling/Selectors.cs

@@ -64,9 +64,12 @@ namespace Perspex.Styling
             Contract.Requires<ArgumentNullException>(match != null);
 
             match.Observables.Add(Observable.Return(match.Control.TemplatedParent is T));
-            match.InTemplate = true;
             match.SelectorString += '%' + typeof(T).Name;
-            return match;
+
+            return new Match(match)
+            {
+                InTemplate = true,
+            };
         }
 
         public static Match OfType<T>(this Match match) where T : IStyleable