diff --git a/src/terminal.c b/src/terminal.c
index 683b74f..fde7721 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -6562,7 +6562,7 @@
     if (argvars[1].vval.v_list->lv_first == &range_list_item
 	    || argvars[1].vval.v_list->lv_len != 16)
     {
-	emsg(_(e_invalid_argument));
+	semsg(_(e_invalid_value_for_argument_str), "\"colors\"");
 	return;
     }