You win, what were they thinking!!, it would look better if the gray was black some shrubbery will help to cover the difference as Retro said

Age has definite advantages! Dr Retro said it all...an Airbnb customer couldn’t care less about that. Nice landscaping suggestions, as ever, from Julie. Enjoy the income and investment potential.

I understand how you feel, and maybe in time you will get something you enjoy looking at. We use AirBnB and truly, outside colour is something we couldn't care less about. We do care about spaces and provisions and preferably having a good shower, and a working kitchen (even if small) and a really really comfortable bed. For a few days or weeks, we can happily live with colours we wouldn't let into our house. And yes, landscaping to hide some of it would be beautiful, especially with really hardly plants.

I sympathise with you and if you can ever convince them to paint over the blue it would definitely look better as the two dark, cool colours together create quite a harsh appearance. If your parents wont budge then yes I think you need to landscape to draw attention away from the these two strong colours, focusing especially on plants with a light tone and texture that will soften the look of the home. Silver toned plants and landscaping materials would really compliment both the dk blue and dk grey and lessen their severity, as would willowy grass plants which look beautiful against a dark background and that could be strategically planted in front of areas where the grey-boards-meets-blue-house are really noticeable. You could also add some large silver/grey feature rocks, weathered timber or line paths with silver gravel to further soften the look and draw attention away from the two dark colours

This a beach house, make life easy and just paint the lower part blue to match the upper walls perfect for this position and climate no need to change the pergola as it works,

Just work on salt sand wind tolerant plants and ones that are easy care not requiring a lot of water.

I guess I'am not the norm but having just left the holiday accommodation industry I want the lot exterior and interior spaces are both as important. That's been my experience with guests as well.

These days with Air B&B there's a lot of accommodation choices and I mean a lot, so if you want to keep the Bookings at a good level and having great return guests, fix it, attention to detail is extremely important, we respond to our surroundings. If you have a shack with multi million $ views don't worry changing a thing the guests will be blinded by the view.

agreeing with other ideas but keep in mind that what we might hate in a permanent home could feel daring and adventurous in a holiday house