Used rainbow streamers and white balloons and swagged them. Turned out cute! The rainbows over the doors are constructed from poster board paper, paint or markers, crepe paper, and for some of the clouds, white balloons.
This rainbow cloud and rainbow dash were so fun to make. I cut a cloud out of a very large piece of white card stock. Then taped streamers across the back of the cloud. It made a beautiful back drop for the cake table.