array keys should be 0, 1, and 2. key 3 results in error (invalid offset)
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index dc7d362..a226ae8 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -1091,7 +1091,7 @@
$txt_color = str_split(substr($this->wm_font_color, 1, 6), 2);
$txt_color = imagecolorclosest($src_img, hexdec($txt_color[0]), hexdec($txt_color[1]), hexdec($txt_color[2]));
$drp_color = str_split(substr($this->wm_shadow_color, 1, 6), 2);
- $drp_color = imagecolorclosest($src_img, hexdec($drp_color[0]), hexdec($drp_color[2]), hexdec($drp_color[3]));
+ $drp_color = imagecolorclosest($src_img, hexdec($drp_color[0]), hexdec($drp_color[1]), hexdec($drp_color[2]));
// Add the text to the source image
if ($this->wm_use_truetype)