diff --git a/lib/class-Shoestrap_Color.php b/lib/class-Shoestrap_Color.php
index f23ae6757c..b4a4b94790 100644
--- a/lib/class-Shoestrap_Color.php
+++ b/lib/class-Shoestrap_Color.php
@@ -18,7 +18,7 @@ public static function sanitize_hex( $color ) {
 			$color = str_replace( '#', '', $color );
 			
 			// Check if this is a valid hex color
-			if ( empty( $color ) || ctype_xdigit( $color ) ) {
+			if ( empty( $color ) || ! ctype_xdigit( $color ) ) {
 				return '#ffffff';
 			}