diff --git a/gtk2_ardour/themes/dark-ardour.colors b/gtk2_ardour/themes/dark-ardour.colors
index f8d43a8d19..fe602af5a8 100644
--- a/gtk2_ardour/themes/dark-ardour.colors
+++ b/gtk2_ardour/themes/dark-ardour.colors
@@ -416,6 +416,7 @@
     <ColorAlias name="stretch clock: edited text" alias="theme:contrasting alt"/>
     <ColorAlias name="stretch clock: text" alias="theme:contrasting clock"/>
     <ColorAlias name="sync mark" alias="theme:contrasting clock"/>
+    <ColorAlias name="region mark" alias="theme:contrasting selection"/>
     <ColorAlias name="tempo bar" alias="neutral:background2"/>
     <ColorAlias name="tempo curve" alias="widget:blue"/>
     <ColorAlias name="tempo marker" alias="widget:orange"/>
@@ -503,6 +504,6 @@
     <Modifier name="transparent region base" modifier="= alpha:0.6"/>
     <Modifier name="time stretch fill" modifier="= alpha:0.5"/>
     <Modifier name="verbose canvas cursor" modifier="= alpha:0.4666"/>
-    <Modifier name="region marker" modifier="= alpha:0.8"/>
+    <Modifier name="region mark" modifier="= alpha:1.0"/>
   </Modifiers>
 </Ardour>