Some colors are hard to see

[ad8e]

For example, here is a smoothed line and its original line. However, the original line is white enough that it is not visible. You can tell it's there because the background grid is interrupted occasionally.

The third line (at 2.8e-7) is pale enough to be hard to see, but it's readable with some effort.

[ainoam]

Thanks for reporting @ad8e. We'll fix the color assignment in coming versions.