diff --git a/gtk2_ardour/themes/diehard3-ardour.colors b/gtk2_ardour/themes/diehard3-ardour.colors
index 459a0ee382..a204f6724b 100644
--- a/gtk2_ardour/themes/diehard3-ardour.colors
+++ b/gtk2_ardour/themes/diehard3-ardour.colors
@@ -319,7 +319,7 @@
     <ColorAlias name="pluginui toggle: fill" alias="widget:bg"/>
     <ColorAlias name="pluginui toggle: fill active" alias="widget:blue"/>
     <ColorAlias name="preference highlight" alias="alert:yellow"/>    
-    <ColorAlias name="processor automation line" alias="theme:bg1"/>
+    <ColorAlias name="processor automation line" alias="alert:green"/>
     <ColorAlias name="processor auxfeedback: fill" alias="theme:contrasting alt"/>
     <ColorAlias name="processor auxfeedback: led active" alias="alert:green"/>
     <ColorAlias name="processor control button: fill" alias="neutral:background"/>