LaTeX/Colors

Adding colors to your text is supported by the color package. Using this package, you can set the font color, text background, or page background. You can choose from predefined colors or define your own colors using RGB, Hex, or CMYK. Mathematical formulas can also be colored.

Adding the color package

To make use of these features, the color package must be imported.

\usepackage{color}

Alternatively, one can write:

\usepackage[usenames,dvipsnames,svgnames,table]{xcolor}

The \usepackage is obvious, but the initialization of additional commands like usenames allows you to use names of the default colors, the same 16 base colors as used in HTML. The dvipsnames allows you access to more colors, another 64, and svgnames allows access to about 150 colors. The initialization of "table" allows colors to be added to tables by placing the color command just before the table. The package loaded here is the xcolor package.

If you need more colors, then you may also want to look at adding the x11names to the initialization section as well, this offers more than 300 colors, but you need to make sure your xcolor package is the most recent you can download.

Entering colored text

The simplest way to type colored text is by:

\textcolor{declared-color}{text}

where declared-color is a color that was defined before by \definecolor.

Another possible way by

{\color{declared-color} some text}

that will switch the standard text color to the color you want. It will work until the end of the current TeX group. For example:

\emph{some black text, \color{red} followed by a red fragment}, going black again.

The difference between \textcolor and \color is the same as that between \texttt and \ttfamily, you can use the one you prefer. The \color environment allows the text to run over multiple lines and other text environments whereas the text in \textcolor must all be one paragraph and not contain other environments.

You can change the background color of the whole page by:

\pagecolor{declared-color}

Entering colored background for the text

\colorbox{declared-color}{text}

If the background color and the text color is changed, then:

\colorbox{declared-color1}{\color{declared-color2}text}

There is also \fcolorbox to make framed background color in yet another color:

\fcolorbox{declared-color-frame}{declared-color-background}{text}

Predefined colors

The predefined color names are

black, blue, brown, cyan, darkgray, gray, green, lightgray, lime, magenta, olive, orange, pink, purple, red, teal, violet, white, yellow.

There may be other pre-defined colors on your system, but these should be available on all systems.

If you would like a color not pre-defined, you can use one of the 68 dvips colors, or define your own. These options are discussed in the following sections

The 68 standard colors known to dvips

Invoke the package with the usenames and dvipsnames option. If you are using tikz or pstricks package you must declare the xcolor package before that, otherwise it will not work.

\usepackage[dvipsnames]{xcolor}

Defining new colors

If the predefined colors are not adequate, you may wish to define your own.

Place

Define the colors in the preamble of your document. (Reason: do so in the preamble, so that you can already refer to them in the preamble, which is useful, for instance, in an argument of another package that supports colors as arguments, such as the listings package.)

Method

You need to include the xcolor package in your preamble to define new colors. In the abstract, the colors are defined following this scheme:

\definecolor{name}{model}{color-spec}

where:

• name is the name of the color; you can call it as you like
• model is the way you describe the color, and is one of gray, rgb, RGB, HTML, and cmyk.
• color-spec is the description of the color

Color Models

Among the models you can use to describe the color are the following (several more are described in the xcolor manual):

Examples

To define a new color, follow the following example, which defines orange for you, by setting the red to the maximum, the green to one half (0.5), and the blue to the minimum:

\definecolor{orange}{rgb}{1,0.5,0}

The following code should give a similar results to the last code chunk.

\definecolor{orange}{RGB}{255,127,0}

If you loaded the xcolor package, you can define colors upon previously defined ones.

The first specifies 20 percent blue and 80 percent white; the second is a mixture of 20 percent blue and 80 percent black; and the last one is a mixture of (20*0.3) percent blue, ((100-20)*0.3) percent black and (100-30) percent green.

\color{blue!20}
\color{blue!20!black}
\color{blue!20!black!30!green}

xcolor also feature a handy command to define colors from color mixes:

\colorlet{notgreen}{blue!50!yellow}

Using color specifications directly

Normally one would predeclare all the colors as above, but sometimes it is convenient to directly use a color without naming it first. To achieve this, \color and \textcolor have an alternative syntax specifying the model in square brackets, and the color specification in curly braces. For example:

{\color[rgb]{1,0,0} This text will appear red-colored}
\textcolor[rgb]{0,1,0}{This text will appear green-colored}

Creating / Capturing colors

You may want to use colors that appear on another document, web pages, pictures, etc. Alternatively, you may want to play around with rgb values to create your own custom colors.

Image processing suites like the free GIMP suite for Linux/Windows/Mac offer color picker facilities to capture any color on your screen or synthesize colors directly from their respective rgb / hsv / hexadecimal values.

Smaller, free utilities also exist:

• Linux/BSD: The gcolor2 tool (usually also available in repositories)
• Microsoft Windows: The open-source Color Selector tool.
• Apple Macs: Hex Color Picker for creating custom colors and the built-in DigitalColor Meter for capturing colors on screen.
• Online utilities: See here for a Wikipedia article with several external links

Spot colors

Spot colors are customary in printing. They usually refer to pre-mixed inks based on a swatchbook (like Pantone, TruMatch or Toyo). The package colorspace extends xcolor to provide real spot colors. They are defined with, say:

\definespotcolor{mygreen}{PANTONE 7716 C}{.83, 0, .40, .11}

Sources

• The xcolor manual
• The color package documentation