diff --git a/ui/src/game/Board.svelte b/ui/src/game/Board.svelte
index cb9289e..ffb2e89 100644
--- a/ui/src/game/Board.svelte
+++ b/ui/src/game/Board.svelte
@@ -297,7 +297,9 @@
     border-radius: 0;
   }
   .grid.gridless .cell.dark {
-    background: color-mix(in srgb, var(--cell-bg) 88%, #000);
+    /* A gentle checkerboard tint: enough to read the alternation without competing with the
+       bonus cells. Lightened from a stronger mix that looked too contrasty in light theme. */
+    background: color-mix(in srgb, var(--cell-bg) 94%, #000);
   }
   .grid.gridless .cell.filled,
   .grid.gridless .cell.pending {