Press the marker button to start. Press "n" to switch drawing utensils. Switch the color for the color of the paint. Clones can get a little laggy so switch it to stamps if you want drawing to stay. Go to the red background and move the "BackgroundColor" slider for different colors. Press "b" to turn off the "Background color to sprite color" button. Press space to hide the variables. Press "v" to switch outlines. If you have a mouse pad, it may be hard to draw so instead of pressing down on the mouse pad press "c" instead.
I was inspired to make this because of @Kind_Account 's project: https://scratch.mit.edu/projects/431426341/