This is purely proof of concept mixed in w/ some testing of concepts. The factors of the sirkel (the not-quite-circle) cannot be changed; they're simply for demonstration. However, the other four variables shown on the screen can be changed: if you press the R key and the up or down arrows, the red factor of the pen will change accordingly. The same happens with the other colors, as well as the transparency of the pen (credit for that particular code goes to Scratch-Minion). You can also make broader changes with the sliders.
I used Scratch-Minion's ARGB code for the transparent pen, but everything else is my code, including the little circle dude and the fader-shady-thing-person. Yes. Never mind. Either way, feel free to add the sprites to your own collection! Schneeballs