diff --git a/programs/tree.rb b/programs/tree.rb
index caa0caf..afff0fd 100644
--- a/programs/tree.rb
+++ b/programs/tree.rb
@@ -5,6 +5,7 @@ def setup
   $colors = ["green", "mediumaquamarine", "lightgreen", "turquoise", "limegreen"]
   
   createCanvas($xSlide * $split, $ySlide * $split)
+  background("black")
 end
 
 def draw