I would suggest painting the wall with the shelves. Pick a colourful graphic print you love, and then use that to determine what colour paint to use, to bring it all together. I also really like the idea of a thick vertical stripe instead of painting the whole wall - you could go for something quite dark/bright/dramatic without it taking over the whole room.
I seem to remember a rule of thumb for decorating is 70:20:10? Ie, mostly 1 colour (in your case white), then 20% another (black I think from your photos) and 10% highlight, ie Teal or pink or whatever rocks your boat. Change the blind, it doesn't have to co-ordinate with the other blinds - making it different will help "zone" the open plan, and reiterate that it is a different room.
Most of all, have fun! Don't go overboard price wise, and if you decide you hate the colour paint, the blind or whatever, you can always change it.
You could also put together a mood board, or use Pinterest to find things you like. You won't need to worry about if it matches or not, just pick things you like, and after a while you are bound to see a common theme - I'm a sucker for all things bohemian, but actually realised that my Pinterest lounge is all very mid-century, scandi g-plan style!
Good luck! And post pics when it is done!