You could add rattan accents or ikat pillows on the sofa. Here are some great, rope-inspired crochet pillows from Pottery Barn: http://www.potterybarn.com/products/paper-crochet-pillow-cover/?pkey=e%7Ccrochet%2Bpillows%7C3%7Cbest%7C0%7C1%7C24%7C%7C1&cm_src=PRODUCTSEARCH||NoFacet-_-NoFacet-_-NoMerchRules-_-

and, some ikat pillows: http://www.allmodern.com/DwellStudio-P10-53-53-DWL2519.html

Can you take it back?
I can't imagine anything less appropriate for a beach place - or anything less comfortable to sit on after a day at the beach...
A pair of plain white cotton duck or twill slipcovered Pottery Barn sofas would be much more suitable, inviting and soothing on sunburned skin - and easy to clean since the slipcovers can just be tossed in the washer w/ some bleach - unlike dark shiny pleather which is just going to be hot and sticky...
...and if you have animals - it's not going to be all that durable either due to their claws.