Update color_filter.cs

com.unity.uiwidgets/Runtime/widgets/color_filter.cs

 namespace Unity.UIWidgets.widgets {
     
         public class ColorFiltered : SingleChildRenderObjectWidget {
-            protected ColorFiltered(
+            public ColorFiltered(
                 ColorFilter colorFilter = null, 
                 Widget child = null, 
                 Key key = null)
         }
 
     
-}
+}