Click to start drawing. Click again to stop drawing. 0 to erase all. Colors: Red=95-5 Orange=6-12 Yellow=13-17 Green=18-41 Sea=42-46 Cyan=47-50 Blue=51-59 Indygo=60-72 Purple=73-82 Pink=83-94 Set Brightness to 100 and Saturation to 0 for eraser.
Unfortunately the dot that follows your cursor doesn't change brightness or saturation, but it chages color and size.
