I also agree with the neutral lounge to be jazzed up with coloured pillows and such. It won't be too much with your feature walls plus, if your taste changes, you paint or you move down the track, the beige will be a lot easier to work with :)

This is a better picture of the blue half feature wall! And the olive is behind it

Hi KC Good looking room. Perhaps using the complimentary colour (yellow) in warmish tones - i.e. not cool, 'sour' tones. Or, have a look at a split complimentary of sherbet colours of orange and green. Would rose pink be suitable? The leather seems to have a pinkish tinge to it. To test the ideas you have, buy some flowers in the colours you are considering - that way you can enjoy the flowers even if the colour doesn't appeal!! You can include the chosen colours in soft furnishings,lamps, glassware, floor cushions,candles, plant containers. Add fun with zigzag stripes or maybe even polka dots! Go for it and have fun.

In general I'd probably say purple couch? No, I don't think so. But I have seen a few that look good. And the one in the picture you have posted is beautiful and suits that room so well.