diff --git a/Models/ReactionTest.cs b/Models/ReactionTest.cs
--- a/Models/ReactionTest.cs
+++ b/Models/ReactionTest.cs
@@ -82,6 +82,17 @@ namespace DesertPaintCodex.Models
             }
         }
 
+        private bool _whiteShift;
+        public bool WhiteShift
+        {
+            get => _whiteShift;
+            set
+            {
+                _whiteShift = value;
+                NotifyPropertyChanged(nameof(WhiteShift));
+            }
+        }
+
         public bool IsAllCatalysts { get; }
 
         private Reaction? _reaction;
@@ -152,13 +163,14 @@ namespace DesertPaintCodex.Models
         public bool IsStub { get; }
 
 
-        public ReactionTest(Reagent reagent1, Reagent reagent2, Reaction? reaction, ClipType clipType, bool isStub = false)
+        public ReactionTest(Reagent reagent1, Reagent reagent2, Reaction? reaction, ClipType clipType, bool whiteShift, bool isStub = false)
         {
             Reagent1 = reagent1;
             Reagent2 = reagent2;
             UseFirstBuffer = true;
             IsAllCatalysts = reagent1.IsCatalyst && reagent2.IsCatalyst;
             Clipped = clipType;
+            WhiteShift = whiteShift;
             Reaction = reaction;
             State = (reaction != null) ? TestState.Saved :
                 (clipType == ClipType.None) ? TestState.Untested : TestState.ClippedResult;
@@ -253,6 +265,7 @@ namespace DesertPaintCodex.Models
                                 if (!extrapolated) extrapolated = ExtrapolateWhiteFromOneChannel(_observedColor.Green, 255, reaction.Green);
                                 if (!extrapolated) extrapolated = ExtrapolateWhiteFromOneChannel(_observedColor.Blue,  255, reaction.Blue);
                             }
+                            WhiteShift = extrapolated;
                         }
 
                         if (!extrapolated)
diff --git a/Models/ReactionTestService.cs b/Models/ReactionTestService.cs
--- a/Models/ReactionTestService.cs
+++ b/Models/ReactionTestService.cs
@@ -34,7 +34,7 @@ namespace DesertPaintCodex.Models
                     Reaction? reaction = profile.FindReaction(reagent1, reagent2);
                     ClipType clipType = profile.PairClipStatus(reagent1, reagent2);
                     
-                    ReactionTest test = new(reagent1, reagent2, reaction, clipType)
+                    ReactionTest test = new(reagent1, reagent2, reaction, clipType, false)
                     {
                         Clipped  = clipType,
                         Reaction = reaction,
diff --git a/Util/Constants.cs b/Util/Constants.cs
--- a/Util/Constants.cs
+++ b/Util/Constants.cs
@@ -21,7 +21,7 @@ namespace DesertPaintCodex.Util
                     _stubReactionTest = new ReactionTest(
                         new Reagent("Toad Skin", "ToadSkin", 48, 96, 48, 0), 
                         new Reagent("Falcons Bait", "FalconBait", 128, 240, 224, 1), 
-                        null, ClipType.None, true);
+                        null, ClipType.None, false, true);
                 }
 
                 return _stubReactionTest;
diff --git a/Views/ReactionTestView.axaml b/Views/ReactionTestView.axaml
--- a/Views/ReactionTestView.axaml
+++ b/Views/ReactionTestView.axaml
@@ -134,6 +134,11 @@
                 <views:ReactionUnitView Reaction="{Binding ReactionTest.Reaction}"/>
             </StackPanel>
 
+          <views:EmbeddedWarningBox Title="🛈 EXTRAPOLATED REACTION"
+                                    IsVisible="{Binding ReactionTest.WhiteShift}"
+                                    Message="One component of the reaction clipped, but a value could be extrapolated from the shift in the color components.">
+          </views:EmbeddedWarningBox>
+
             <views:EmbeddedWarningBox Title="🛇 REACTION CLIPPED"
                                       IsVisible="{Binding !!ReactionTest.Clipped}"
                                       Message="Your reaction fell outside of measurable values. We will need to use a buffer pigment to test it.">