Address color-similarity issue

[kateharwood]

Because we are using fixed colors for the forecasters (so they don't change when the plot updates) and because we are using colorblind friendly colors, many of the forecasters have really similar colors and are hard to differentiate.

We could include a reshuffle colors button, so when you have selected the forecasters you want to see, you can press the button and it will redistribute the colors in a better way so you can tell the forecaster lines apart.

We could also add different line types and see if that mostly solves the problem.

[kateharwood]

Added different linetypes, issue not as high priority now.