colordiff: 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/colordiff - from package: colordiff

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

On Debian possible default full paths are:

/usr/bin/colordiff - from package: colordiff

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

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