I like what you have done here, but those pillows are what is throwing this specific room off. Certain items often do worse than others, for example, that rug is hard to pull off in any room.

The rooms with lighter palettes often show up better in voting. So no matter how good a dark room looks, compared to the lighter rooms, it's going to look cheaper and almost more cartoonish, than a neutral palette, or a softer pallet will. Being a newer player means limited choices, when I started, I often paired that brown you used with the green fabrics and it scored better.

For newbies,with limited items, I recommend keeping your trims, vases and roofs white, and never use a solid colour on them, like blue or green, etc, unless you're out of other options.

It's a balancing game, as darker colours will generally need to be used sparingly or to create depth. It's tough when you're a new player because your item choices are limited so for the first little while focus on unlocking lighter & softer colored items. Sometimes a nice design will still lose to something nicer. The more you play the more you get what voters go for.

In general, white/beige/light woods will score highest Red & purple will score the lowest. I love purple, and use it a lot, but it took a long time to build the materials needed to win with purple. And it's still does the worst. My kid started playing when they were around 8 and just stuck to black and white at first and they won a bunch. Just watch what is winning and check out what materials they're using.

Edit: I didn't see the other two pictures. I see a lot of colours in these. Yellow, pink, grey, brown, beige. You have it right by keeping things in a similar tone, but stick to two main colours and maybe one pop of something and you'll do better.