Use mlines instead of drawing an extraneous line.
The extraneous line was not supposed to be visible, i.e., by setting alpha=0, but this resulted in invisible line style in the legend, which is obviously not what we want.
Note the pull request by @JanOpper also tried to fix this issue.
But that approach will make the extraneous line showing up in the plots.
Also I prefer the original PALLETE (this is the name of variable in the original codebase) instead of the uniformly drawn colors, shown here.
The old palette has colors more vivid to me.
Use mlines instead of drawing an extraneous line. The extraneous line was not supposed to be visible, i.e., by setting alpha=0, but this resulted in invisible line style in the legend, which is obviously not what we want.
Note the pull request by @JanOpper also tried to fix this issue. But that approach will make the extraneous line showing up in the plots.
Also I prefer the original PALLETE (this is the name of variable in the original codebase) instead of the uniformly drawn colors, shown here. The old palette has colors more vivid to me.