Basically to draw you just use your mouse. To make the thickness do up arrow and down arrow. Up arrow to make it thicker down is skinnier. For right arrow and left it just changes the shadiness (aka Saturation) of it. click something to make the color. It was fun making this.
This had mostly been inspired by my sister who likes to draw. 100 views = new colors... She really liked it I hope you do! If you want type in the comments to add any color.