diff --git a/theme/37c3/theme.json b/theme/37c3/theme.json
index f048eeb31..85c477663 100644
--- a/theme/37c3/theme.json
+++ b/theme/37c3/theme.json
@@ -93,7 +93,7 @@
     "button-background": "#2d42ffff",
     "button-selected": "#2d42ffff",
     "calendar-bg-color": "#000000ff",
-    "lines-color": "#0b1575f",
+    "lines-color": "#aaaaaaff",
     "day-number": "#aaaaaaff",
     "day-number2": "#aaaaaaff",
     "time-color": "#0481f5",