Add colorblind safe and printer friendly options to color_scheme_set

[VeenDuco]

It would be nice to have colorblind safe and printer friendly options to choose with the color_scheme_set() function. Options for this can be found via here.

One option that would satisfy both critera is the color scheme #b2182b #ef8a62 #fddbc7 #d1e5f0 #67a9cf #2166ac.

[tjmahr]

We do provide the four viridis palettes, plus the fifth cividis palette has been added in a different branch. But maybe it could be easier to switch to Brewer palettes.

[avehtari]

But maybe it could be easier to switch to Brewer palettes.

For backward compatibility it's good to keep the old ones, but it would be great to be able easily to choose from brewer palettes, too.

@VeenDuco which plot in bayesplot you were specifically thinking now?

[VeenDuco]

@avehtari I didn't have a specific plot in mind, I want to offer it as an option in shinystan for all plots which I would set using color_scheme_set.

[avehtari]

I want to offer it as an option in shinystan for all plots which I would set using color_scheme_set.

I would list there all named Brewer palettes and the existing bayesplot palettes

[VeenDuco]

Allright, I will do that.

[jgabry]

We could certainly allow something along the lines of:

bayesplot::color_scheme_set("brewer-PuBuGn")

which would set the color scheme to six colors from the PuBuGn brewer palette. (I'm using palette names from https://moderndata.plot.ly/create-colorful-graphs-in-r-with-rcolorbrewer-and-plotly/). To do this we would need to do one of the following:

• hardcode the palettes in the master_color_list:

bayesplot/R/bayesplot-colors.R

Lines 341 to 346 in 3922b87

	master_color_list <- list(
	blue =
	list("#d1e1ec", "#b3cde0", "#6497b1", "#005b96", "#03396c", "#011f4b"),
	brightblue =
	list("#cce5ff", "#99cbff", "#4ca5ff", "#198bff", "#0065cc", "#004c99"),
	darkgray =

• or add a dependency on the RColorBrewer package and use RColorBrewer::brewer.pal() to generate them on the fly.

Either way would work I think.

[jgabry]

@VeenDuco I can set up a branch of bayesplot with the brewer palettes so you can use that branch to test it out with the new shinystan stuff you are working on.

[jgabry]

Ok @VeenDuco go ahead and check out the brewer-palettes branch and PR #190

[jgabry]

I just deleted that branch so that won’t work anymore, but the PR was merged so you can just use the master branch.