Options to customize default colors

[bwiernik]

I'm colorblind and use a dark theme in my editor. Whenever a package uses crayon::red(), I can't see the text at all. Would it be possible to add an options system to let users to specify different colors to use for the base crayon color functions? For example, the option to specify options(crayon.red = "coral3") to use the "coral3" color instead of the base R "red" color for red text.

If this is reasonable, I would be happy to do a pull request.

[gaborcsardi]

Unfortunately creating aliases for the built in color functions will not take you very far, because people can define new ones using things like crayon::make_style("pink").

Do you know if there is a way to convert generic RGB colors to a colorblind friendly palette?

[bwiernik]

There are a variety of color blindness simulators (e.g., https://github.com/MaPePeR/jsColorblindSimulator) that could perhaps be backwards engineered. ColorBrewer can also generate “colorblind safe” pallets (e.g., https://github.com/axismaps/colorbrewer/). Perhaps some code from there would be helpful. (Edit: No it looks like ColorBrewer just has a set of specific colorblind friendly palletes.)

The issue though, is that there are six major different types of colorblindness that each have distinct contrast issues, and the impact of any type of colorblindness is really dependent on the context. For example, my type of colorblindness (strong protanomaly) makes everything darker and makes it really difficult to distinguish the base R red (fairly dark) from either black text or a black background. Most other colors don’t have major contrast issues for me.

While some form of automated colorblindness filtering would certainly be nice, I’m not sure how feasible or resource efficient that would be. Most packages seem to use primarily use the base color functions, and for ones that don’t, contacting their developers to make their color choices more accessible is always an option. I basically only run into major usability issues with crayon::red, and being able to change that would solve >95% of the issues with my form of colorblindness.

[gaborcsardi]

Thanks! For the 256 color case I think we could have palettes, which are basically mappings from color names to RGB. These could be configured by the end user.

The 8 color case is trickier, because there is no pink, etc. OTOH some tools, e.g. iTerm let you map the 8 ANSI colors to anything. Maybe RStudio has something similar. What is your editor?

[bwiernik]

I use RStudio.

[gaborcsardi]

@bwiernik i am sorry this has taken so long: #329.

I will merge it after the CI checks and then you can try it easier, if you are interested.

The dichro palette is hopefully better for everyone:

options(cli.palette = "dichro")
cli::ansi_palette_show()

This is how it looks currently:

The cli package will supersede crayon, but I can port this back to crayon as well, so the hundreds of packages currently depending on crayon will use the same palette.

Suggestions for palette changes and new palettes are most welcome! Thanks, and sorry again.

[gaborcsardi]

The PR closed this, I did not mean to close it just yet.

[bwiernik]

Wow! This is awesome! The built in palettes work great for me. If you could back port this to crayon, that would be amazing!

[bwiernik]

And well worth the wait! Really appreciate you implementing something as robust and flexible as this!

[gaborcsardi]

@bwiernik Thanks for the feedback. I'll go ahead with this then.