diff --git a/dm_control/locomotion/soccer/pitch.py b/dm_control/locomotion/soccer/pitch.py
index c8f88a54..b87ea707 100644
--- a/dm_control/locomotion/soccer/pitch.py
+++ b/dm_control/locomotion/soccer/pitch.py
@@ -131,7 +131,7 @@ def _build(self,
           self._mjcf_root.worldbody.add(
               'geom',
               type='box',
-              rgba=[.3, .3, .3, .3],
+              rgba=[.3, .3, .3, .0],
               pos=wall_pos,
               size=wall_size))
     # Build roof.