diff --git a/plugins/PostProcessingPlugin/scripts/ColorMix.py b/plugins/PostProcessingPlugin/scripts/ColorMix.py
index 4a2ff718bb..1152ba70da 100644
--- a/plugins/PostProcessingPlugin/scripts/ColorMix.py
+++ b/plugins/PostProcessingPlugin/scripts/ColorMix.py
@@ -150,7 +150,7 @@ class ColorMix(Script):
             startLayer = firstHeight
             endLayer = secondHeight
         #see if one-shot
-        if self.getSettingValueByKey("c_behavior") == "fixed_value":
+        if self.getSettingValueByKey("behavior") == "fixed_value":
             endLayer = startLayer
             firstExtruderIncrements = 0
         else:  #blend