I love the colours in your rug. I would use those colours for inspiration Navy blue, grey. What colour is your wall?

Instead of navy blue I would use an ice blue, google dupioni silk pillow covers. The shine will contrast with the couch fabric.

Not a Pro.

You can shop on Houzz. Put in your colors and shape of the pillow and sooooo many to pick from.

Here is some inspiration:

Graz Geometric Pillow Sky Blue 20"x20" · More Info

My walls are a light pale yellow. I'm wondering if I do three pillows on each side on the three seater and 2 on each side on the two seater. what shape - square or lumber.

Here is the perfect guide to pillow arranging

http://www.stonegableblog.com/5-no-fail-tips-for-arranging-pillows/

Don't be afraid to mix your traditional home with modern furnishings, that can be the most stunning combo. There are so many furnishing possibilities here, you could have a furniture store do some renderings for you to get ideas flowing.

I got mustard

Very pretty space. You're talking about ten pillows total; that's probably too many. They'll end up on the floor. The guide linked by petsr4keeps above does a great job with color and patterns, but she uses too many pillows, so many there's no room on the sofa to sit.

If you have trouble coordinating pillows, RH has some fabulous collections. They're ungawdly expensive, but you might do two special pillows and then find plain ones to coordinate.

Patterned Pillows | RH · More Info

Ikat Silk Velvet Pillow Cover · More Info

Indigo Tie Dye Ripple Lumbar Pillow | World Market · More Info

Indigo Tie Dye Ripple Throw Pillow | World Market · More Info

Oversized Indigo Blue Geometric Stripe Lumbar Pillow | World Market · More Info

I love RH and bought grey velvet and fuzzy ones from them. But didn't love the look on the sofa.

Beautiful rug! Can I ask where you found it?

You definitely need more than two pillows (one on each end) on your large sofa and loveseat. Your space would look great with several pillows in various colours and textures and a nice deeper coloured throw.. Good luck :)

Rebecca I got it at Costco of all places

Thank you but not my style

it is ok edel, do you know what you do want more or less, i have hundreds and will be happy to keep looking. those were a quick choice that carried the right colors etc.