There are lots of fabrics out there that are not floral prints - think Grunge, etc. Instead of focusing on fabric prints, focus on quilt pattern and color combos, such as:
blue and green
blue and tan
blue and white
green and white
red and blue
orange and black
black and blue
and so on.
Just FYI - my 27 year old son picked, as his favorite quilt I've ever made, a zigzag quilt made from pastel batiks that included soft green, pale blue, pale pink, coral, yellow. He said it looked summery.