colrconv: command not found

Have You tried accessing the binary with the full path?

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/colrconv - from package: colrconv

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