diff --git a/desktop_postinstall.sh b/desktop_postinstall.sh
index 47c140c..3d47ab0 100644
--- a/desktop_postinstall.sh
+++ b/desktop_postinstall.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 # Copyright (C) 2021-2024 Thien Tran
 #
diff --git a/install.sh b/install.sh
index ae22fa7..27667bb 100644
--- a/install.sh
+++ b/install.sh
@@ -15,7 +15,7 @@
 # the License.
 
 output(){
-    echo -e '\e[36m'"$1"'\e[0m';
+    printf '\e[1;34m%-6s\e[m\n' "${@}"
 }
 
 unpriv(){
diff --git a/update_grub.sh b/update_grub.sh
index e61f1d9..c272885 100644
--- a/update_grub.sh
+++ b/update_grub.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 # Copyright (C) 2021-2024 Thien Tran
 # Licensed under the Apache License, Version 2.0 (the "License"); you may not