I would say you need 3 1/4 yards. Just to be safe (and make the math easier) I'd bump it up to 3 1/2 yards. Divide that by 6 different fabrics and you'll need about 5/8 of each.
I always err on the side of caution, so I'd probably get 3/4 yard, but that's just me. I'd use the leftovers for binding or another project.
Hope this helps!