Replace qualitative color palette in visualizations

[snide]

This is an imperfect, but much better colorblind-safe palette that @Adrian-J and I like for chart usage.

#00B3A4
#3185FC
#DB1374
#490092
#FEB6DB
#F98510
#E6C220
#BFA180
#920000
#461A0A

Beyond these 10 colors, when more are needed we should either do one of two things:

1. Cycle the colors again in order.
2. Modify the palette above by a luminosity percentage (likely alternating a positive value first, then a negative one) for each new series of 10. This will only scale so far, eventually the series will become too dark or too light to be readable, so you'll still need to eventually cycle.

The larger the palette becomes, the more impossible it becomes to scale against colorblindness. I'll leave it to you which system you think is best.

[markov00]

@snide I'm using this vis color palette on a stacked bar chart but, at least for a normal color viewer (for color blind seems work correctly), the contrast seems a bit too much high between green blue and red, especially between blue/red one, and it's quite eye disturbing.
What do you think about?

[snide]

We have pretty strict guidelines on accessibility and contrast. It's difficult coming up with a set of ten colors that work against those requirements and that somewhat match our brand and that work on a dark background. Generally they tend to come out hot.

[markov00]

I perfectly understand the difficulties there 👍
What do you think about having a different palette order for some visualizations? so high contrasting colors are mixed with lesser contrasting colors? like: green - yellow - blue - pink - red etc?

[snide]

Feel free to adjust the order as you think works best. The blue should likely be first though.

[monfera]

Great work, it's quite hard to make a 10-element qualitative color palette that's suitable for various vision strengths and weaknesses and this palette is doing well. As it's common to use just two, or just a few of these colors, putting more contrasting ones at the beginning would be good, for example with the current order, the first two are hard to tell apart:

Monochrome:

Deauteranopia, which is the most common (others are similarly close in the first two positions):

Even in full color they're a close pair esp. with thin lines or small points:

[myasonik]

This issue has a closed PR associated with it. Is there anything left to do for this? (Not for addressing color blindness issues with visualizations more broadly, but specifically for replacing the old palette with the newer palette.)

[markov00]

cc @stratoula @flash1293

[flash1293]

We are working on this right now - it's planned for 7.12 @stratoula do we need to keep this issue? I guess there's another one tracking this.

[stratoula]

As Joe said, we are working on it. We plan to migrate to the new palette for the xy axis and pie charts for 7.12 and eventually to the other charts. No need to keep this 🙂