Brown,
White dress shirt with black slacks and black comfortable shoes
You can go either way.
yes
No, have black shoes with black pants. Brown with black and it looks like you don't know better. No style.
Brown.
Ew, NO! Black and navy blue don't match!!! Neither do black and brown! I don't suggest wearing blue slacks with black shoes!
yes
Some dress slacks are wrinkle free and do not need to be ironed.
brown and black
Semi formal wear can mean anything from a woman wearing slacks and a blouse; skirt and blouse and flat shoes if she prefers to men wearing a sports jacket with either a shirt and tie or a shirt open at the neck and slacks to slacks and a shirt or slacks and a sweater.
You can wear any type of dress you like, but not necessarily long. It is also acceptable to wear summer slacks (in summer of course) with a nice top and sandal shoes (high heel or low.)
Black or brown