You mean to complement the floral chair? It's the living room? What does the room look like? Is there carpet, an area rug on hardwood?

Take pictures, add more context. The sofa and loveseat are in front of a fireplace? What color are the walls?

See what I mean? More context is needed to your question.....

Otherwise? A pretty pale green: )

Seating items like this would complement the rose floral chair.

I’d go with a nice light wide green and white stripe.

https://www.tonicliving.com/products/conway-stripe-fabric-sage

Since the sofa in the picture has a busy design, you need to set it off by using a sofa and a couch in a simple fabric, preferably without a design. Use white or light beige, or use one of the colors of the pattern in the sofa in the picture, which is light green or light pink. And then complete the set by using cushions in the color or design of that sofa or the same fabric.

Green will avoid it becoming too sweet: :) and will keep the pretty. Don't' forget pillow's

This might look nice: (or it may be too yellow, I’d definitely want to see a sample)

https://www.perigold.com/decor/pdp/schumacher-montebello-stripe-fabric-tcbj4528.html?piid=62256645

or this:

https://www.perigold.com/decor/pdp/schumacher-summerside-stripe-fabric-tcbj2893.html?piid=50800196

or if you wanted to pick up both the pinks and greens:

https://www.perigold.com/decor/pdp/the-house-of-scalamandre-ariel-stripe-silk-fabric-thsc1501.html

You could also do gingham - green or pink, or even a lavender - colors aren’t rendering great on my screen