Colour scheme for bid price buckets

[prakaa]

In short, the colour scheme as is works and there is plenty of contrast between colours, but I wonder if the scheme could be made more intuitive for people interpreting the plots:

1. Option 1: Choose a categorical (could retain existing), sequential and diverging colour scheme, and add a checkbox so a user can choose which they prefer to view the data with. Ideally you could choose between colour schemes, but this might require a fair bit of effort to implement?
2. Option 2: Change the default to either sequential or diverging.

I think diverging could be good, particularly if the colour scale can be "centred" at $0/MWh. This way, you can distinguish negative and positive offers. On the other hand, there are far more buckets that are positive, so using a diverging scale might reduce contrast between positively priced offer buckets.

Some sites that might help:

1. https://colorbrewer2.org/#
2. http://vrl.cs.brown.edu/color
3. https://www.sessions.edu/color-calculator/

[nick-gorman]

Thanks @prakaa for the suggestions. I've put together a potential diverging colour scheme, and would be interested in your thoughts. I've tried to match up the discrete and continuous schemes as well.

[prakaa]

Thanks @prakaa for the suggestions. I've put together a potential diverging colour scheme, and would be interested in your thoughts. I've tried to match up the discrete and continuous schemes as well.

@nick-gorman: I think the discrete works well, although as I mentioned before it might be a little hard to differentiate some bands. The outline on each bar segment (i.e. white outline) helps a lot though.

Re continuous, the contrast in high prices is obscured. Is that intentional? Not sure if it can be done, but a contrast based on a log scale for the continuous chart might help?