6 inch 35 min (for 2) 31 min (for 1)
Cake Flavor: Lemon 
Filling: Lemon Curd
Frosting: I used a cream cheese frosting and added 1 tsp fresh lemon juice, and 1/2 tsp lemon extract.

I tried the watercolor technique using different flavors of buttercream frosting. Here's what I want to remember for next time:

1. For watercolor, it's probably best to use a all butter buttercream, not cream cheese. The cream cheese frosting was more difficult to get smooth, and you can't fuss with the frosting too much when your trying for the watercolor look. The result was a less finished looking cake, but super delicious. 
2. Don't only crumb coat your cake before adding your colors--completely frost with your base color and then add your colors. Otherwise you end up with WAY too many gaps and holes in your frosting, which means going over it more times, which will change the look of your cake.
3. Using brighter colors will photograph better.
4. When doing a half moon decoration, cover more than you think.
5. Make sure your buttercream dam for your filling is completely secured to your cake so you don't have any leaks.