colorout is an R package that colorizes R output when running in a Unix (e.g. Linux and OS X) terminal emulator; it does not work on Microsoft Windows. The relevant code is written in C and, thus, it runs very quickly and you should not note any slowdown in R output.

R's stdout is parsed and numbers, negative numbers, dates in the standard format, strings, indices, and R constants are identified and wrapped by special ansi escape codes that are interpreted by terminal emulators as commands to colorize the output.

R's stderr is also parsed to identify the expressions "warning" and "error" and their translations to many languages. If these expressions are found, the output is colorized accordingly; otherwise, it is colorized as "stderror" (magenta, by default).

Screenshot:

You can install the latest release version of the package from R-multiverse:

install.packages('colorout', repos = 'https://community.r-multiverse.org')

You can install the development version by running the following commands in a terminal emulator:

git clone https://github.com/jalvesaq/colorout.git
R CMD INSTALL colorout

Some people prefer to use devtools to install packages from github.

NOTES:

• The package cannot be on CRAN because it changes code already loaded by R and this is prohibited by the CRAN Repository Policy. The package replaces the functions that output results and messages to R Console, and this is necessary because we cannot colorize the output without replacing these functions.

• Because the package is not on CRAN, it is better to load it with require() rather than library() to avoid error in your ~/.Rprofile after upgrading R.

• You should load colorout only when you can actually see R's output, not when running R non-interactively (see example on the next section). This will avoid unnecessary error messages in some circumstances (in the languageserver log, for instance).

You can customize the colors according to your preference, guided by the color table made by the command show256Colors(). You can also set the colors to any arbitrary string. In this case, it is up to you to set valid values.

You can also call the function addPattern() to set your own patterns to be colorized.

Example of how to load colorout from your ~/.Rprofile:

if (interactive() || isatty(stdout())) {
    options(colorout.verbose = 1)
    if (require("colorout", quietly = FALSE)) {
        # Gruvbox color scheme by @sjlva
        colorout::setOutputColors(
            index    = "\x1b[38;2;215;153;33m",
            normal   = "\x1b[38;2;235;219;178m",
            number   = "\x1b[38;2;211;134;155m",
            negnum   = "\x1b[38;2;104;157;106m",
            zero     = "\x1b[38;2;69;133;136m",
            infinite = "\x1b[38;2;250;189;47m",
            string   = "\x1b[38;2;184;187;38m",
            date     = "\x1b[38;2;254;128;25m",
            const    = "\x1b[38;2;250;189;47m",
            true     = "\x1b[38;2;142;192;124m",
            false    = "\x1b[38;2;251;73;52m",
            warn     = "\x1b[38;2;250;189;47m",
            stderror = "\x1b[38;2;204;36;29m",
            error    = "\x1b[38;2;204;36;29m",
            verbose  = TRUE
        )
    }
}

Try different colors and, when happy with your colorscheme, change colorout.verbose to 0, quietly to TRUE, and verbose to FALSE. If you don't understand the color codes above, see #27 (comment).