Your home also reminds me of the look that
www.wisteria.com/Furniture/departments/1001 shows on their online website.
I could see some of the things from this store working in your house.
Accessories:Aqualife Pillow covers mixed with sold linen ones
Decorative ogjects: Sea Treasure Jar- Glass jars with soft white/tan shells. My SIL has many around her house and they are so pretty. Natural things from nature as accent pieces.
Some of the vases here are also pretty.
The one flower wall art in pink is nice. I think a soft flower photo wall picture print is great. I have bought many nice original photos from
www.Etsy.com and have a theme of women in the ocean wearing white lace dresses.
I still think layering white on whites/cream will give you the calm better than major pops of color. But it depends on the look you want. My formal living room has whitewashed Pergo floors, white Ikea chaise loungers and chairs, a whitewashed armiore with mirrors from Restoration Hardware and whitewashed side table. I have silver mercury glass lamps. Accents on the wall are photographs from a famous photographer of women in the desert wearing white lace dresses with white horses. His work was originally featured in Vogue for these pictures but he released them to buy and I had one made that is probably 4 by 3 feet on the wall in back of my couch. I have white linen and crochet balloon curtains on the 2 windows so alot of light is in the room and it is calm. I did paint the ceiling light blue to pick up colors from the photos but all the walls are white as well as the chair rail and ceiling moluldings. I bought Rachel Ashwell Cabbage Rose -blue roses on very light linen throw pillows for the furniture. After seeing your room I feel I can continue with the silver mercury glass/silver color in more accent pieces.
I think the idea of flowers for color is nice because you can change them around. I have bought pink, white, lavender, and perwinkle blue silk hydrangeas in a glass vase with the fake water and rocks on the bottom as a huge centerpiece for my dining room table a few years ago. It was stunning.
Your house really seems so perfect right now. I wouldn't do any major changes but keep the serene feeling with light touches. Perhaps a tablecloth for the table and throw for the couch along with pillows.
Also if you have Home Goods in your area I find them a great sorce for beautiful accent pieces for the house, their pillow section was huge, nice art too. Good luck. I would love to see pictures of your other rooms.