Colorblind friendly plotting

[brownsarahm]

Colorblind learners cannot tell if their code works in the visualization episode. it would be good to also teach how to change the pallete to a friendly one or at least also change the line style.

[phillybroadbent]

The RColorBrewer library has colourblind friendly palettes, which can be accessed from display.brewer.all(colorblindFriendly=TRUE) . To improve accessiblity for colourblind users further, the colourblindr package provides colour palettes that are accessible to users with different types of colour blindness. This information could be added to the customization section of the lesson.

[tobyhodges]

Thanks both for contributing to this discussion. The lesson underwent a major update and reorganisation when #887 was merged. As this issue relates to content in a version of the lesson before that update took place, I will close it. Colourblindness is addressed in the context of colour palettes in the Changing Scales section of the current content. Please open a new issue if you believe that further improvements could be made in this regard, linking to this thread where appropriate.