I put a purple paper clip on the beginner piano classes' page in their piano book. The clip was used to attach an additional song to practice that isn't in their book. They all had the loose sheet along with the paper clip at the next lesson. My piano kids love this color! I've decided to use purple paper clips and purple Post-It notes for everything.
I have a feeling there will be some purple crayons used when the students color the king's royal crown.