The only fight I saw with Colbert was against Curtis Parker in what was one of the most unbelievably dull fights of all time, mainly due to Colbert's stalling tactics. What I have read is that he was a dull and difficult guy to fight. Maybe that's why he didn't receive more exposure.
Mike Colbert got plenty of ink in Ring Magazine during the
1970s. He was managed by a well-known Portland manager
named Mike Morton, who also handled Ray Lampkin.
When the ill-fated A.B.C./Ring Magazine American Boxing
Tournament took place, Colbert was one of the participants.
Based on what I saw in that tournament, Colbert was a
boxer-type who ran alot while throwing a left jab.
It is ironic that a number of top American fighters weren't
invited into the said tournament while there were a number
of mediocre club fighters participating. Heck! I don't think
that Marvin Hagler was invited! It should also be noted that
there was another tournament taking place at the same time
with the bouts being shown on a network of independent
stations in the United States. The production values of
the telecasts of the latter weren't very good, but there
were a number of terrific bouts on the shows, including
one between Vito Autofermo and Eugene "Cyclone" Hart.
But both tournaments ended prematurely due to the scandal
surrounding the A.B.C./Ring Magazine Tournament.
By the way......Hagler stopped Colbert in a bout after the
tournaments ended.