CO raises a lot preflop but has been passive a lot post flop
SB has been pretty quiet.
30 hands maybe.,

PokerStars Pot-Limit Omaha High, $0.25 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

SB ($31.25)
Hero ($27.75)
UTG ($19.45)
MP ($14.75)
CO ($39.20)
Button ($22.15)

Preflop: Hero is BB with 6, T, Q, 6.
UTG calls $0.25, MP calls $0.25, CO calls $0.25, Button calls $0.25, SB completes, Hero checks.

Flop: ($1.50) 6, K, 9 (6 players)
SB bets $1.45, Hero calls $1.45, UTG folds, MP folds, CO raises to $7.25, Button folds, SB calls $5.80, Hero folds.

correct?

Yes.

Yeah, you played it good. If it was 99 or KK you may be able to see the turn, but even then it's borderline at best.

Good fold.

E Z fold

Ok, for the interest of discussion, do we fold KK and 99 as well?

I think I would, but it would be far more reluctantly.

With zero implied odds? I guess so.

huh?

Why 0 implies odds?
You make 0 if it pairs?

We could be against a lower set if we had KK.

Noone pays you off if they have a flush on a paired board (or rather your implied odds are extremely limited), and if somehow they do have a lower set then the board will only pair very rarely (4 outs to win a big pot, and 1 out to lose a big pot).

they do in my games.,

In that case, you are probably justified in calling with KK/99 here.