pal2rgb: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/pal2rgb - from package: libtiff

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pal2rgb - from package: libtiff-tools

You may install the required package with command apt-get install {package}

Error in other languages:
pal2rgb: bevel nie gevind nie
pal2rgb: comandă negăsită
pal2rgb: comando não encontrado
pal2rgb: commande introuvable
pal2rgb: command not found
pal2rgb: käsku ei ole
pal2rgb: không tìm thấy lệnh
pal2rgb: komanda nerasta
pal2rgb: Kommando nicht gefunden.
pal2rgb: kommandot finns inte
pal2rgb: komut yok
pal2rgb: nie znaleziono polecenia
pal2rgb: níor aimsíodh an t-ordú
pal2rgb: no se encontró la orden
pal2rgb: no s'ha trobat l'ordre
pal2rgb: opdracht niet gevonden
pal2rgb: parancs nem található
pal2rgb: perintah tidak ditemukan
pal2rgb: príkaz nenájdený
pal2rgb: příkaz nenalezen
pal2rgb: команда не найдена
pal2rgb: командата не е открита
pal2rgb: 命令找不到
pal2rgb: コマンドが見つかりません