Have you ever used the "Change Color Effect" block? It will change the look of your sprites. Did you notice there is a drop down menu with other effects? No? Well good news, this program will show you how each of those effects work! Just click each number and watch what happens to Scratch.
The challenge for Day 10 was to explore a new block. In case you didn't notice... I chose the "Change ___ effect" block. It is hiding in the "Looks" section. There are seven different "effects" that you can use, so this program demonstrates what they do! You can test them out here, without changing the looks of your sprite and then having to add in that pesky "Clear effects" block at the beginning of your script ;-)