diff --git a/Models/ReactionTest.cs b/Models/ReactionTest.cs
--- a/Models/ReactionTest.cs
+++ b/Models/ReactionTest.cs
@@ -212,25 +212,25 @@ namespace DesertPaintCodex.Models
                     {
                         Reaction? reaction = CalculateReaction();
                         bool extrapolated = false;
-                        
+
                         // SPECIAL CASE:
                         // Check to see if we've got a white-shift reaction that's partially clipped, where we can
                         // still extrapolate the reaction, based on the available information.
                         if (!testing3Way && (reaction != null))
                         {
                             PaintColor baseColor = _recipe.BaseColor;
-                            if ((reaction.Red < baseColor.Red) &&
-                                (reaction.Green < baseColor.Green) &&
-                                (reaction.Blue < baseColor.Blue))
+                            if ((reaction.Red < 0) &&
+                                (reaction.Green < 0) &&
+                                (reaction.Blue < 0))
                             {
                                 // White-shift down clip.
                                 extrapolated                    = ExtrapolateWhiteFromOneChannel(_observedColor.Red,   0, reaction.Red);
                                 if (!extrapolated) extrapolated = ExtrapolateWhiteFromOneChannel(_observedColor.Green, 0, reaction.Green);
                                 if (!extrapolated)                ExtrapolateWhiteFromOneChannel(_observedColor.Blue,  0, reaction.Blue);
                             }
-                            else if ((reaction.Red > baseColor.Red) &&
-                                (reaction.Green > baseColor.Green) &&
-                                (reaction.Blue > baseColor.Blue))
+                            else if ((reaction.Red > 0) &&
+                                (reaction.Green > 0) &&
+                                (reaction.Blue > 0))
                             {
                                 // White-shift up clip.
                                 extrapolated                    = ExtrapolateWhiteFromOneChannel(_observedColor.Red,   255, reaction.Red);
@@ -300,7 +300,8 @@ namespace DesertPaintCodex.Models
             BadReaction = null;
             Clipped = ClipType.None;
             State = TestState.Untested;
-            
+            ObservedColor = null; // Clear it out
+
             UpdateRecipe();
         }