If it's going long term, I would go with a flooring that is very cleanable and is an opposite color of the existing wood floor. 

Going down in 3 weeks to pick final Paint colors.  

You can get them in many colors to match the finish.

In Wisconsin: race, color, national origin, religion, sex (including pregnancy, childbirth, and related medical conditions), disability: physical or mental, age (40 and older), genetic information, marital status, sexual orientation (includes having a history of or being identified with a preference), arrest or conviction record, military service, off-duty use of lawful product. --- Milwaukee also adds on top of that: source of Income.)

I also think conveying that in future marketing that you can supply a fridge (color their choice) or possibly give them credit off their rent for supplying their own.I would look at what my competition is doing in the area, if they are all supplying fridges then that might be the problem.

They both agreed on the color of the wall-wall carpet for the 1st floor.Burgundy. 

Most come off with mineral spirits and scrapingMy question:  has anyone used a shoe polish, or can recommend to me a coloring substance to repair floor!

The nice thing is that you could mix and match colors.

I then spray gun painted them with two coats of primer and two color coats.

You can finish them in whatever color matches the rest of the flooring.