When we went to look at house the basement was painted one color (sky blue) when we bought gr house and went to do final walk through I noticed there were dabs of dark blue paint all over the floors.

Also, if the property is in a historic district or register, that could significantly limit your options on (typically) exterior upgrade/design to things like the windows, trim replacement, paint color & scheme, etc.

As long as the island granite/quartz countertop blends well with an overall design, does it matter what color I get?

Below is the color for the interior that I am dying to do, so I’m having a hard time imagining anything to go with that.Is white a no-go?

Now on to your question about how to tell if the property is in the high-risk flood zone. look at the photo I have attached the light blue color symbolizes the high-risk flood zone sometimes you may see an area in orange on this map that is usually the shaded X zone.

I'd like to build a rental portfolio in the area and flip some houses, starting with one for my family to live in (see above).If you are in Fort Myers, Gateway, Estero, Bonita Springs, Naples, Cape Coral, Sanibel, Lehigh Acres, or anywhere else in that general area, please reach out!

This makes is much easier to remember/know what paint color and type to have ready for repainting and touch ups.

Paint for sure, don't use strong colors just some off white for walls and white for molding and doors.Not sure how big is the apartment, refinish wood floors id you have or install engineered wood or bamboo flooring, there are some good looking cheap options (check build direct)But bathrooms and kitchens make the big difference, if you are doing the renovation yourself, check with IKEA kitchens, you can get some nice cabinets what will give a fresh look for not much money.. also you could just replace the wall cabinets if the base ones are decent and could be refurbuished The counters are tricky because big money require quartzite counter tops that are pretty expensive, but there are some OK options. 

specify a color., must be moved when they leave?

And I can only start with what I have ;)Risking letting my newbie colors show, Dollar General?