diff --git a/apps/rgb/app.js b/apps/rgb/app.js
index aa18d93ae..373ee6f54 100644
--- a/apps/rgb/app.js
+++ b/apps/rgb/app.js
@@ -1,4 +1,5 @@
 const rgb = [0, 0, 0];
+const hex = '0123456789ABCDEF';
 const w = g.getWidth();
 const h = g.getHeight();
 function drawToggle (value, x, y, options) {