xaringancolor

The goal of xaringancolor is to allow you to change the colors uniformly across text, equations, and code.

Installation

You can install the package with:

# install.packages("devtools")
devtools::install_github("EmilHvitfeldt/xaringancolor")

This package will most likely never be put on CRAN.

How to setup

xaringancolor only contain 1 function; setup_colors(). Pass the colors you want to use in as named arguments. Please be careful and use simple names, preferably letters only, no numbers, spaces, or other characters.

library(xaringancolor)
setup_colors(
  red = "red",
  green = "green",
  blue = "blue"
)

Running this code includes some lines of code into your clipboard. Paste this into the beginning of your xaringan document. After you have done that you can delete the above code, you won’t be needing it anymore.

How to use

HTML

css classes named according to the colors have been created, so if you want some text to be red you type .red[my text] and text inside the square brackets turn red. This only works for the colors you have created and you need to put a leading period (.) before the color name when you use the css class.

Equations

A LaTeX macro has been created for each color. Use them as follows

$$\red{Y} = a \blue{X} + b$$

and Y will be colored red and X will be colored blue.

Code

A variable for each color has been created. These can be used directly in plots such as with geom_abline(..., color = red) but they can also be used with flair.

Start with a named chunk with both include and eval set to FALSE. This is the code you want to highlight

``{r mtcars_mean, include=FALSE, eval=FALSE}
lapply(mtcars, mean)
``

then you add another chunk with echo=FALSE where you use the decorate() to select the previous chunk by name and flair() to denote which parts of the code should be colors which way. Use the color variables here to achieve uniform coloring throughout the presentation.

``{r, echo=FALSE}
decorate("mtcars_mean") %>%
  flair("mtcars", color = red) %>%
  flair("mean", color = blue)
``

See this link for more information on how to use flair.

How it works

The code will look something like the code below and serve 3 main purposes. The first section defines the LaTeX colors and the second section uses Mathjax to generate LaTeX macros which allow us to use colors in the equations.

<div style = "position:fixed; visibility: hidden">
$$\require{color}\definecolor{red}{rgb}{1, 0, 0}$$
$$\require{color}\definecolor{green}{rgb}{0, 1, 0}$$
$$\require{color}\definecolor{blue}{rgb}{0, 0, 1}$$
</div>

<script type="text/x-mathjax-config">
MathJax.Hub.Config({
  TeX: {
    Macros: {
      red: ["{\\color{red}{#1}}", 1],
      green: ["{\\color{green}{#1}}", 1],
      blue: ["{\\color{blue}{#1}}", 1]
    },
    loader: {load: ['[tex]/color']},
    tex: {packages: {'[+]': ['color']}}
  }
});
</script>

The third section defines a <style> tag with sets the colors so we can use them in the html text.

<style>
.red {color: #FF0000;}
.green {color: #00FF00;}
.blue {color: #0000FF;}
</style>

And the fourth and final section creates a R chunk that sets us up to use flair package. It loads the package and defines character vectors that specify the colors.

``{r flair_color, echo=FALSE}
library(flair)
red <- "#FF0000"
green <- "#00FF00"
blue <- "#0000FF"
``