diff --git a/data/theme/gtk-styles.css b/data/theme/gtk-styles.css
index a5f75ee0..01e5bfb2 100644
--- a/data/theme/gtk-styles.css
+++ b/data/theme/gtk-styles.css
@@ -443,6 +443,10 @@ monthcell label {
     font-size: 0.9rem;
 }
 
+monthcell.out-of-month label {
+    color: alpha(@theme_fg_color, 0.66);
+}
+
 monthcell:hover:not(.out-of-month) {
     background-color: @theme_bg_color;
     transition: background-color 200ms;