Thank you for sharing how to make them!
I would think, if all you were doing was the side of a garage or something, you could even manage a simple block on a 2' x 2' piece of plywood, especially since you are working with solid colors ... good point about texturing the colors being just a lot of work.
We have a foundation down below the house and shop that I have been wanting to do that on for every since we got here, but it never occured to me to make it in the winter <g> (I am soooo slow! LOL) ... and when the weather gets nice, like you, I have other things to do ... what a great thread! <wave>