A nice plain color pillow will look good with all the marble print. Also the long rectangular shape will look good as well.
Blush, Grey and Copper On trend Colour Schemes Liv with Vision - bedroom
Rose gold dream on marble background throw pillow cushion on
Pink and grey gradient cubes throw pillow - rose gold cushion on
black and white triangles Throw Pillow by Her Art. I like the triangle design idea to use leftover pieces of fabric from my couches/chair recovering.