Colin Loss was in the Norwich youth side of the early 1990s after being spotted playing for Rangers Youth in Plymouth by a Norwich scout. Despite training with Plymouth Argyle, Colin opted to trial at Carrow Road as Plymouth didn't really have a youth-team set-up. He signed schoolboy forms and then joined as a YTS trainee.

However he failed to make the first team at Carrow Road and transferred to Derby County. Failure yet again to make a first team appearances saw Colin drift into non-league football with Gresley Rovers.

Bristol City saw potential in Colin and signed him up on professional terms. He made 5 appearances for Bristol City before returning to non-league football with Merthyr Tydfil. He joined League of Wales sides Barry Town (twice) and Ebbw Vale before returning to Merthyr in September 1997. Colin later joined League of Wales side Carmarthen Town but returned to Merthyr for his third spell at Penydarren Park. He was transfer-listed in May 2000 but was only released by the club in May 2001. After a spell playing for mid-Wales side Rhayader, Colin signed for fellow League of Wales side Haverfordwest County managed by former Norwich youth team colleague Deryn Brace.

In October 2005, Colin joined Merthyr Tydfil for the fourth time. He returned to the Welsh Premier League towards the end of February 2006, joining Carmarthen Town