diff --git a/src/components/CalendarDay.vue b/src/components/CalendarDay.vue
index af40cfb..b68648b 100644
--- a/src/components/CalendarDay.vue
+++ b/src/components/CalendarDay.vue
@@ -94,7 +94,7 @@ const handleEventClick = (eventId) => {
   text-shadow: 0 0 0.1em var(--strong);
 }
 .cell.selected {
-  filter: brightness(0.8);
+  filter: hue-rotate(180deg);
 }
 .cell.selected h1 {
   color: var(--strong);