diff --git a/README.md b/README.md
index a92542e..7212bf5 100644
--- a/README.md
+++ b/README.md
@@ -165,7 +165,7 @@ documentation below for more information.
 The ouput file MUST use the PNG extension.
 
 ```php
-$waveform = $audio->waveform(640, 120);
+$waveform = $audio->waveform(640, 120, ['#00FF00']);
 $waveform->save('waveform.png');
 ```