diff --git a/gtk2_ardour/themes/cubasish-ardour.colors b/gtk2_ardour/themes/cubasish-ardour.colors
index 03e3b614fb..6edabe127b 100644
--- a/gtk2_ardour/themes/cubasish-ardour.colors
+++ b/gtk2_ardour/themes/cubasish-ardour.colors
@@ -109,9 +109,9 @@
     <ColorAlias name="ghost track wave clip" alias="neutral:background"/>
     <ColorAlias name="ghost track wave fill" alias="neutral:foregroundest"/>
     <ColorAlias name="ghost track zero line" alias="neutral:foreground2"/>
-    <ColorAlias name="grid line major" alias="neutral:foregroundest"/>
+    <ColorAlias name="grid line major" alias="neutral:backgroundest"/>
     <ColorAlias name="grid line micro" alias="neutral:midground"/>
-    <ColorAlias name="grid line minor" alias="neutral:foreground2"/>
+    <ColorAlias name="grid line minor" alias="neutral:background2"/>
     <ColorAlias name="gtk_arm" alias="alert:red"/>
     <ColorAlias name="gtk_audio_bus" alias="widget:blue darker"/>
     <ColorAlias name="gtk_audio_track" alias="theme:bg1"/>