--- a\src\gtk\iupgtk_colordlg.c	Sun Jul 26 03:10:04 2015
+++ b\src\gtk\iupgtk_colordlg.c	Wed Jan 17 23:12:37 2018
@@ -48,6 +48,7 @@
     }
     palette = palette_p;
   }
+  free(gtk_str);
   str[off-1] = 0;  /* remove last separator */
   return str;
 }