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https://github.com/matt-dray/coloratio
:white_square_button::black_square_button: R package: check accessibility of color contrasts
https://github.com/matt-dray/coloratio
accessibility color contrast-ratio rstats rstats-package
Last synced: 3 months ago
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:white_square_button::black_square_button: R package: check accessibility of color contrasts
- Host: GitHub
- URL: https://github.com/matt-dray/coloratio
- Owner: matt-dray
- License: other
- Created: 2020-12-24T17:00:30.000Z (about 4 years ago)
- Default Branch: main
- Last Pushed: 2021-05-28T16:48:00.000Z (over 3 years ago)
- Last Synced: 2023-03-05T15:09:43.268Z (almost 2 years ago)
- Topics: accessibility, color, contrast-ratio, rstats, rstats-package
- Language: R
- Homepage: https://matt-dray.github.io/coloratio/
- Size: 219 KB
- Stars: 7
- Watchers: 2
- Forks: 2
- Open Issues: 7
-
Metadata Files:
- Readme: README.Rmd
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
Awesome Lists containing this project
README
---
output: github_document
---
```{r, include = FALSE}
knitr::opts_chunk$set(
collapse = TRUE,
comment = "#",
fig.path = "man/figures/README-",
out.width = "100%"
)
```
# {coloratio}
[](https://www.repostatus.org/#concept)
[](https://github.com/matt-dray/coloratio/actions)
[](https://codecov.io/gh/matt-dray/coloratio?branch=main)
[](https://www.codefactor.io/repository/github/matt-dray/coloratio/overview/main)
[](https://www.rostrum.blog/2020/12/30/coloratio/)
This work-in-progress R package helps calculate color-contrast values so you can make decisions to improve the visual accessibility of your R outputs. You can [read a blog post about it](https://www.rostrum.blog/2020/12/30/coloratio/).
It was originally developed with the need for selecting high-contrast text colors for use on block-colored backgrounds. The ultimate aim is to create a tool for compliance with [WCAG 3.0](https://w3c.github.io/silver/guidelines/).
Feel free to add an issue or a make a pull request. Please follow [the code of conduct](https://www.contributor-covenant.org/version/2/0/code_of_conduct/).
## Similar tools
[The {savonliquide} package](https://github.com/feddelegrand7/savonliquide) by [Ihaddaden M. El Fodil](https://twitter.com/moh_fodil) achieves the main aim of this package using [the WebAIM contrast checker API](https://webaim.org/resources/contrastchecker/). It's [available on CRAN](https://CRAN.R-project.org/package=savonliquide).
## Installation
You can install the development version of {coloratio} from GitHub with:
```{r install, eval=FALSE}
remotes::install_github("matt-dray/coloratio")
```
## Examples
### Get contrast ratio
The `cr_get_ratio()` function returns the color-contrast ratio of two user-provided colors. You can provide hex values, named colors, or both.
```{r ratio-example}
library(coloratio)
cr_get_ratio("#000000", "white")
```
You should aim for a value of 4.5 or greater. You'll get a warning if the contrast between the colors is insufficient.
```{r ratio-example-warning}
cr_get_ratio("black", "grey10")
```
[Read more about the calculation](https://www.w3.org/TR/WCAG/#dfn-relative-luminance) in the WCAG 2.1 guidance.
### Color contrast demo
`cr_get_ratio()` also lets you view a plot of text on a block background using the supplied colors by setting `view = TRUE`.
```{r demo-example, out.width='50%'}
cr_get_ratio("#000000", "olivedrab", view = TRUE)
```
You can access this visual functionality in isolation with `cr_view_contrast()`.
```{r demo-2-example, out.width='50%'}
cr_view_contrast("blue4", "sienna1")
```
### Choose black or white
You may want to alter programmatically the color of overlaying elements when the underlying color varies. For example, when putting text over the bars of a grouped bar chart.
The function `cr_choose_bw()` returns `"white"` or `"black"` depending on which has the better contrast ratio with the user-supplied color.
```{r bw-example-gray}
# Supply a character vector, receive a character vector
cr_choose_bw(c("gray10", "gray90", "lightyellow"))
```
Black is chosen in the event of a tie.
### Choose a high-contrast color
You can use `cr_choose_color()` to check a user-supplied color against all named R colors and return those with greatest contrast.
```{r col-example}
cr_choose_color("midnightblue")
cr_choose_color(
col = "olivedrab", # user-supplied color
n = 3, # number of colors to return
ex_bw = TRUE # exclude black, whites, grays?
)
```
You have the option to exclude black, whites and grays from being returned (via the `ex_bw` argument) because they're boring.
## Code of Conduct {#conduct}
Please note that the {coloratio} project is released with a [Contributor Code of Conduct](https://contributor-covenant.org/version/2/0/CODE_OF_CONDUCT.html). By contributing to this project, you agree to abide by its terms.