Feature Request: Reduce overlap on adjacent lines of different colors

[shannonturner]

From Youtube:

When two or more lines are drawn on top of each other, (Example: Using the fill tool to make water) it creates this weird lumpy effect on the lines. Not a huge big deal, but it can definitely make the map look a bit weird, or unintentionally displeasing to look at. If you change make it so that the lines didn’t look lumpy when over lapping each other in the update, that’d be great!

This is especially noticeable when using flood fill.

First, there's a purple line:

After flood fill, it's very difficult to see at all:

Reducing the line width to 12.5% makes it clearer what's happening here:

Here, you can see that the water is connecting across the purple line.