Render text in color for Markdown / Quarto documents

The colorize() function renders text in color for Markdown / Quarto documents. For documents to be rendered in HTML, it uses a CSS <span>; for documents to be converted to LaTeX and rendered as PDF, it uses \textcolor{}{} from the xcolor package.

Usage

colorize(text, color, format = NULL)

colorize_bg(text, color, format = NULL)

Arguments

text: Text to display, a character string
color: Color to use, a valid color designation; if missing, use text as the color
format: character specification of the output format. Currently supported formats are: "latex" (default if is_latex_output), "html" (default if is_html_output, and "text" (otherwise) are supported where the latter just contains the input text without any color formatting.

Value

A character string with the input text along with markup for color encoding.

Details

A companion function, colorize_bg() does the same, but uses the specified color for the background.

The names of colors Note that a color name not defined in the xcolor package will trigger a LaTeX error. e.g., darkgreen is not defined but you can use: \definecolor{darkgreen}{RGB}{1,50,32} in a document to be rendered to PDF.

For inline text, in running text, you can use:

 `r colorize("Gentoo", "orange")` and  `r colorize("Adelie", "purple")` are Penguins.
 The `r colorize("red")` points and the `r colorize("blue")` points are nice

In a chunk, you can also define variables with the names of colors, for ease of use:


 red <- colorize('red')
 pink <- colorize("pink")
 blue <- colorize('blue')
 green <- colorize("green")
 yellow <- colorize("yellow")

Then, these can be used directly in strings, interpolated by glue::glue(). This is particularly useful in figure captions.

Author

Michael Friendly

Examples

# show what the generated text looks like when encoded for either HTML or LaTeX
colorize("red", format = "html") |> cat()
#> <span style='color: red;'>red</span>
colorize("red", format = "latex") |> cat()
#> \textcolor{red}{red}

colorize_bg("blue", format = "html") |> cat()
#> <span style='background-color: blue;'>blue</span>
colorize_bg("blue", format = "latex") |> cat()
#> \colorbox{blue}{blue}

# \donttest{
 red <- colorize('red')
 blue <- colorize('blue')
 green <- colorize("green")
 glue::glue("There are {red} points, {blue} points and {green} points")
#> There are red points, blue points and green points
 # }