@ProxyCell perhaps they called it coleco for brevity's sake.

Anyways it's unlikely that name will be changed as its been in the core of mess for a very long time and would break things.

I named it coleco in the systems here to maintain parity with mess as advmess also uses that system name. You can still theme it by colecovision in ES even if the system is called coleco in the backend.

Related see all systems here:

http://www.progettoemma.net/mess/sysset.php

@auswear https://github.com/retropie/retropie-setup/wiki/EmulationStation#how-do-i-change-the-order-of-the-systems-in-emulationstation