diff --git a/viz/static/js/scene.js b/viz/static/js/scene.js
index 6468c69..9275ec3 100644
--- a/viz/static/js/scene.js
+++ b/viz/static/js/scene.js
@@ -171,6 +171,8 @@ fetch('/api/trajectory')
           pointRadius: 0,
         });
       }
+      Chart.defaults.color = '#556';
+      Chart.defaults.backgroundColor = 'transparent';
       new Chart(document.getElementById('depth-chart'), {
         type: 'line',
         data: { datasets },