Rainbow Bedding Set.
Probably the cheapest way to make a duvet cover is to use the flat sheets the same size as the duvet. Fold over a shorter side of a rectangle one inch. The zipper foot allows you to sew along the belt without bumping into snaps.

Girls Unicorn Bedding

Pink Unicorn Bedding

Purple Unicorn Bedding

Rainbow Colored Comforter Sets

Rainbow Stripe Comforter

Rainbow Unicorn Comforter

Teenage Girl Comforter Sets

Twin Comforter Sets