be aware, CO has many IT glitches relating to AC and class of service. if you're getting a 753 flight listed as BF, you're more than likely getting a flgith that should say "first class." CO's 753's do not have BusinessFirst seats, regardless of what the fare class says.

you can never 100% reley on what co.com says as "class."

your only way to tell for sure is to check the seat map and AC type.

any 737 will have normal dometic FC. any 767 or 777 will have have BF seats. any 753's will have normal domestic FC (sometimes 12 seats and sometimes 24 seats). 752's will have either normal domestic FC seats (24 seats) or BF seats (16 seats).

it all just depends. the last thing to look at is what co.com lists as "class," ie first, intl biz, BizFirst or econ.