gcm-calibrate: 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 Debian possible default full paths are:

/usr/bin/gcm-calibrate - from package: gnome-color-manager

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

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