I would not go with the major color like blue nor choose a deadening color like grey but pick a color that is one of the smallest in use in that pillow.
Choosing a blue or a grey will kill the impact of that beautiful fabric. Matching it dead on is nearly impossible. More often than not it will be a near miss.

Decorating is like making music. It is a combination of high notes and low notes. Many people make the mistake of pairing up the high notes- The color that is predominant. A low note are the touches.
If you were to squint your eyes and look at the color like say jelly beans and sort them into colors in this beautiful pillow into ratios one could say this:
Aqua blue 45%
Soft red 20%
Golden banana 17%
soft green 10%
Brown 5%
Black 3%
By pulling the smaller ones up in your decor you will have a greater success in tying things together. After years of study at Parson School of Design I learned about color theory. And just like cooking you can enhance or kill color by combining. Hold 2 color opposite on the color wheel and they hold each other true but also vibrate.

I would paint the walls in a beautiful shade ( 75% - 50% lighter version) of that banana color and find a striped fabric with the 50-80% soft red in it with a 25% hint of that blue with touches of the other colors for the curtains. Find lively bold art and solid vases in those fun colors with Gerber roses would be beautiful too.