Paint all walls & ceiling (two colors) each unit.

This question pops up frequently on the site, and the most successful investors are looking at the situation pragmatically, not through massive-cashflow rose-colored glasses.You NEED to visit the property before you buy it.

Color?

Basically he is a successful investor who has a big personality and colorful language (seriously don't bring the kids to his meetings). 

For example,In a 20 unit apartment building, all one bedroom one bath and pink in color.18 are rented, 2 vacant.The 18 that are rented for $500 per month.  

If you don't like the color of a room, put that in terms of what that does to the rent.

What website gives Crime map (color coded) - Trulia stopped that since early 2022

Light colored countertops with clean, non veiny surfaces is very popular right now.I see some people throwing in Baltic Brown granite countertops from Home Depot ($30 square foot) and they think they can throw that into a high end renovation.

My wife picks colors for staging and tile back splash, etc.

I would probably ask the real estate agent and ask them which finishes/structures that attracts most clients for the area, they are the front liners of selling, they know that if you have an ugly color combination of red and blue on the bathroom, it wouldn't attract much.