The rug is going to determine your pillows. If you like the rug, then find pillows with black, white, grey in various patterns and textures. Add one new color. The red roses look good in the room, so you might want to add a couple of red pillows. Otherwise, change the rug and find pillows to go with the new rug.

Add pillows in teal / orange / red / grey to add a punch of colour and accent. The rug is too small (if temporary rug) keep that in mind when you buying.