We use a very light beige color (neutral, not cold or warm) and we paint walls, baseboards and trim all one color.  

Depends on color scheme.....Polyurethane looks nice too..

Maybe a coloring book/crayons if they have kids, a chew toy if they have a dog, etc.  

And they chose these wild southwestern style colors - like turquoise and peach and a sick yellow mustard color.  

New properties tend to sell at a slight premium to 10 year old buildings, but that's because everything is new, you get to pick colors and finishes to customize it to your taste. 

Just wanted to share a color scheme that seems to be working well for my rental units.

Here is the Seattle definition: “Discrimination” means any conduct, whether by single act or as part of a practice, the effect of which is to adversely affect or differentiate between or among individuals or groups of individuals, because of race, color, creed, religion, ancestry, national origin, age, sex, marital status, parental status, sexual orientation, gender identity, political ideology, honorably discharged veteran or military status, alternative source of income, participation in a Section 8 or other subsidy program, the presence of any disability, or the use of a service animal by a disabled person.

I'd put a nice carpet runner up the treads, it will protect the treads and should be fairly cheap; pick a good wearing but modern pattern/color for the carpet.

And you got it rented 10 days after the tenant moved out.I think you're letting your dislike for these tenants color your judgment here. 

And I love the light colored granite and the fact that you didn't paint everything gray.