A project I made to show the usability of the pen feature in Scratch. Click Space for Turbo Mode! Click again to stop it. Click the up arrow to set a color. (Your color must be between 1-200) The pen will continue to use that color until you hold down the down arrow key for 3 seconds.
There are a bunch of secrets! For example, try setting a nonexistent color value (one that isn't between 1 and 200)! Also, try using scratch's turbo mode (shift + green flag) and the project's turbo mode!