Fix #2558
diff --git a/system/helpers/captcha_helper.php b/system/helpers/captcha_helper.php
index 2d2ae77..29911dc 100644
--- a/system/helpers/captcha_helper.php
+++ b/system/helpers/captcha_helper.php
@@ -142,7 +142,7 @@
 
 		is_array($colors) OR $colors = $defaults['colors'];
 
-		foreach (array_keys($default['colors']) as $key)
+		foreach (array_keys($defaults['colors']) as $key)
 		{
 			// Check for a possible missing value
 			is_array($colors[$key]) OR $colors[$key] = $defaults['colors'][$key];