If you must do carpet, I would say dark gray or tan.

They don't realize that a lot of what they see is all smoke and mirrors.  

Hi there, this is normal practice however you should not be in the dark.

If it is a cold dark shell, we would do $60-65 psf. 

Of course, YMMV.I would definitely get a good look at the neighborhood around your possbile purchase, and see if you think a nurse would feel comfortable finishing a shift and coming from the hospital to your quadplex alone and in the dark.

Going from a 2-3 unit may also required some additional fire/smoke alarm work.

I have a tenant who is already late on his payments but he was smoking in the property and caused a fire.

You are never kept in the dark about your investment.

Many new investors get excited by high cash on cash returns in the midwest and buy rough properties in D areas and they get smoked by property managers, tenants, vacancy, capital expenses, repairs, turnover costs, etc. 

The home was on the market for an extended period of time because the renters smoked in the home so I was able to get it 20k under asking price.