Anyhow, being a person who has no C$ (Lucky others -_-) and joining in 2016 (WHYYYYY) I've used anything that's relatively close to my favourite colours: Yellow, orange and gold! Hey, it didn't specify to do just one! 
Looking at mine and the others, I'm (not) crying right now because mine looks so... Well, let's just say that they have store-bought items ;-; Anyways, enjoy!