This theme is totally unoriginal. I'm pretty sure one of my StuCo kids found this on pinterest. We modified a few things to make it fit our school.
My students did an awesome job of making posters to hang in the hall to announce each spirit day's dress up theme. The posters have been a new tradition we've started this year. The kids come in one afternoon after school for 3 or so hours. I think it really makes them more invested in the spirit week activities.
Our theme for the week was "There's no place like HOMEcoming." Each day focused on an aspect of the Wizard of Oz.
Monday - Oz the Great and Powerful: Wear your best and brightest green and bling
Tuesday - Twister Tuesday: Dress Wacky (Mismatch Day)
Wednesday - Somewhere Over the Rainbow (Class Color Day)
I was a bit bothered by the fact that not all of these colors are in the rainbow...
Thursday - Lions, Tigers, and Bears. Oh my! (Animal Print Day)
Friday - There's a Storm Coming! (Spirit Day)
This especially fits my school because our mascot is the tornado!