Did something similar for the girls' birthday. Used rainbow streamers and white balloons and swagged them. Turned out cute!
Rainbow Party Backdrop Decorations!
DIY Rainbow Party Invitation
Ape's Eats: Rainbow Birthday Party!
Rainbow unicorn party photo booth
Crepe paper rainbow with fluff covered foam clouds and glitter lightening bolts. Rainbow Unicorn Party!
My little pony party favor idea, diy creaseless hair ties unicorn
So glad my sis sent me this...going to try it for Mia's Hello Kitty themed 3rd birthday party!
Pastel tassel garland from a Pastel Unicorn Birthday Party on Kara's Party Ideas | KarasPartyIdeas.com (4)