I agree with you ,the painting is not the best choice. Maybe get one with some nautical theme ( waves, beach or sea shells). You can just get a poster and frame it in light color frame. The coffee table you can just sand with a fine grit sandpaper to expose original timber and put some clear warnish to finish like the coffee table in the photo. Cushions is easy just get something like in your sample photo, go to spotlight or Target, if you make mistake it's easy to return. Last thing get rid of clutter that is seen in the background . I think couch is fine ,looks comfy.

Hi, You could introduce some mid century pops of colour, mustard , teal and burnt orange. This could be in your dining chairs or cushions and throws and art etc. I would only go with black if you are intending to have black elsewhere as the floor looks like it could be quite dark. If you wanted to go a bit more scandinavian you could accessorise with pale blue soft greys and creams. The Viva creme suite gives scope for introducing more colours than the darker one but it is important to introduce some colour. Good luck.

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I think that top one from Amart will look lovely with the room and will definitely carry on with your timber throughout, it’s different, has a light wood that will pick up the white of the tables, I would love it myself. Are you able to get a larger photo of it and see how it looks near tables.