For your 1st purchase, I would choose black. Once you have all your black bags, then move to color. Since you like light pink, you will probably add it in the near future. Chanel is a very slippery slope and you can't just have one Chanel bag!
I tried on the black but felt like it was going to be too “nice” for everyday use. I ended up getting it in a lovely nude color that I felt was more casual and I would be able to use it every day.