Reduce border on drawing lines
As shown in the screenshot below, the drawing tool uses a white border on either side of the black line. At small sizes, it's hardly noticeable, but when the line is bigger, the border scales up, too, and is distracting. I'd suggest either not having the white border at all, or keeping it small, no matter how thick the line. Not a big deal, but I don't remember seeing a similar effect in other tools.