diff --git a/mono16.s b/mono16.s
index b1ba24c..310d8b1 100644
--- a/mono16.s
+++ b/mono16.s
@@ -112,7 +112,7 @@ wait_loop:
 
         ; 4 cycles after break
         ; Update color registers as fast as possible
-        sta COLPF0 ; 4
+        sta COLBK ; 4
     .endmacro
 
     .macro run_frame frame_offset