Back during the pre-season I made a thread in the NFL Talk forum saying that Colbert was one of the 9ers three likely cuts that the Seahawks should definitely target.
Here's the story on him:
YEAR 1: Drafted in the 7th round as a height/weight/speed guy. Forced into starting in single high role for the second half of the season and played *very well*
YEAR 2: Went in as the starter without competition and with very high hopes. The 9ers secondary was a mess with guys going in and out of the lineup, and there was just a ton of mental lapses and guys not being on the same page (IIRC the 9ers had the same two starting safeties healthy and playing in two or three of sixteen weeks total last year).
Some of those mental lapses were on Colbert, some were on other people. Many of them were just miscommunications.
As an example, Colbert and Witherspoon were the two young secondary players everyone was excited about, and last year both of them were in the total dog house -- so far this year Witherspoon looks phenomenal, it really was just a mess as a unit even though Witherspoon and Colbert got the brunt of the blame for not meeting very high expectations.
Colbert ended up getting hurt and going on IR in week 8 or so.
YEAR 3: Colbert was injured this offseason and didn't really get a chance to compete. When he did get in he quickly got ejected for a targeting penalty (it happened, but it's not a *problem* he has) and then got hurt again. When the 9ers cut him they had to do it with an injury settlement. Colbert was going to be a backup (the coaches *love* Ward for some reason and Moore -- a 3rd round pick last year --- was ascending as a FS (he's the starter now).
Long story short, if he had been healthy this offseason I *strongly believe* he'd be on the team. What happened was that Jimmie Ward broke his hand and they weren't going to put two injured free safeties on the 53 so Colbert got cut and they kept Exum.
Guys in the locker room loved Colbert. The internal media staff for the 9ers really leaned on Colbert and seemed to love Colbert too.
I understand why the 9ers cut him, but I think as a second string FS and special teams players he's an absolute steal.