The style of grown-ish is a bit less frenetic than black-ish, with Shahidi breaking the fourth wall on camera as well as narrating. But more room is given to storytelling and less to graphics and other asides that the parent show does well.
A colleague is someone you work with at your job. When you are a teacher, the other teachers are your colleagues. When you work as a cashier at 7-11, the guy at the deli counter is your colleague as well. Your colleagues are usually people at the same level or rank as you are. You would not usually consider your boss to be a colleague. This noun is from French collÃ¨gue, from Latin collega a person chosen along with another, from the prefix com-with plus legare to appoint as a deputy.
To me, the difference depends on how well you know that person you're working with. A colleague is somebody that you know well enough that you'd spend time with them outside of work, somebody that shares the same interests, thoughts as you. A co-worker is somebody you happen to work with, but not in a close relationship sort of way. For example, a colleague you'd invite over for a gathering or a party of sorts, a co-worker is somebody you interact with mainly at work, and no other place really, unless you happen to cross paths outside of work.