The second home is slightly more expensive, and due to it's higher mortgage payments, its monthly expenses are at 1k/month and is therefor cashflow neutral. 

You could mention to him that you've had several comments concerning the flags, but in the end if there is nothing in the lease you might be out of luck.For future, you could state in the lease that all window coverings must be a solid, neutral colour or have a solid, neutral colour for backing. 

I don't think so we can really hope to do it meaningfully in a cost-neutral way, at least not as long as we don't change the work.

@Mary Mitchell  Modern shades of gray or greige (mix of beige and gray) ARE neutrals. 

We always stick to these three rules: 1) Pick a finish that can withstand a little punishment. 2) Pick a neutral color (beige, light gray, etc.) that goes with anyone's decor. 3) Use the same paint in every property you own and keep a bucket readily available when it is time to touch things up.

Moment she reported I replaced the fridge and later found out it was lose neutral issue which electrician fixed and installed grounding. she cancelled twice the appointment before we could get access to fix this.5. its a 1950's build house so it does not have grounding, i needed to get into home to fix the grounding issue for all outlets.

If there are chips in the paint, holes from hanging photos, or patches of mismatched paint from repairs, I would highly recommend a fresh paint job with neutral colors.

Make sure, as well, that you are lending in first position only and through a neutral party such as escrow or title.

If you do this, when you buy the place remember it isn't your forever home and buy it as a rental (eg you may not like the countertops, but they are neutral and in good shape).

Also, it may end up being cost neutral for the tenants if the alternative is racking up huge late fees.