Hi, trevs is a hill college, built in the '60s. chads is an older college on the bailey and cuths has 2 sites a self catered one and a catered one, the catered is on the bailiey (not sure if they can grant you a catered accommodation or if there is a chance to get moved to the self catered one). In general all colleges have the same facilities and the major things that change between them is formals. Chads has 2 formal each week and they are gowned while cuths and trevs should have less formal. If I'm not mistaken trevs has gowns while cuths doesn't.
The number of students in each college is also important to consider. Chads is the smallest with around 140 freshers and 550 total students, cuths has 1400 total students but if you want to live in the catered accommodation they have only 110 people living there and trevs has around 900 total students. There are pros and cons in being in a small or big college and generally it's personal preference. Also from last year you can rank the colleges but it's still worth remembering that chads is the 2nd, if not the 1st, most competitive college to get in with around 40% of people being accepted, around 75% of people get into cuths and 90% get into trevs (these number are from 2020 so before the ranking was introduced but I think they might be similar). Let me know if you have more questions