Everything you've done so far is very neutral. It blends together the two different areas in one open space, yet I think you'd get a more pleasing effect defining them and adding interest. In the simple form of one dimensional carpet you can achieve this. I would suggest a bright and geometric carpet as a stark contrast to the neutral, coordinating (that same mustard) or using opposite (Aubergine?) or tertiary (brighter yellow and goldenrod or into greens) colours with the cushions to separate living from dinning while also bringing continuity. When it comes to colours, ask yourself how you want to feel in this space. Choose colour to guide your mood. Two other small details: 1. The lamp beside the couch should be higher and darker. That charcoal you've used would be an appropriate colour repetition here. 2. The art on the wall above the dinning table is too small. What about bigger and brighter, but keep a charcoal element in either the frame or the art? Lovely job so far :)

Hi, can't see the rug you're talking about?

That's a good idea! could even get them seen together...

I think you feel it looks too solid is because you haven’t followed through with the rest of the room, for example cushions to tie in with it. Further up these comments minnie101 has suggested some black patterned cushions which i think would lift the scheme, however if you really don’t like it then follow your heart and return it. Why keep something you don’t like? Then choose a colour-way that you prefer, such as the blue you suggested. A blue coastal theme would tie in nicely with the neutral theme you have at the moment. By the way, i got a Turkish rug from Olney Carpets in Bucks, and they let us take it home for a week to see if we liked it before buying! True service, and yes we did buy it! Of course buying online does give you that option too. I wish you lots of luck.