# Beamer Bibliography Font Color In Html

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LaTeX enables typesetting of hyperlinks, useful when the resulting format is PDF, and the hyperlinks can be followed. It does so using the package hyperref.

## Hyperref

The package hyperref[1] provides LaTeX the ability to create hyperlinks within the document. It works with pdflatex and also with standard "latex" used with dvips and ghostscript or dvipdfm to build a PDF file. If you load it, you will have the possibility to include interactive external links and all your internal references will be turned to hyperlinks. The compiler pdflatex makes it possible to create PDF files directly from the LaTeX source, and PDF supports more features than DVI. In particular PDF supports hyperlinks. Moreover, PDF can contain other information about a document such as the title, the author, etc., which can be edited using this same package.

## Usage

The basic usage with the standard settings is straightforward. Just load the package in the preamble:

This will automatically turn all your internal references into hyperlinks. It won't affect the way to write your documents: just keep on using the standard - system (discussed in the chapter on Labels and Cross-referencing); with hyperref those "connections" will become links and you will be able to click on them to be redirected to the right page. Moreover the table of contents, list of figures/tables and index will be made of hyperlinks, too. The hyperlinks will not show up if you are working in draft mode.

### Commands

The package provides some useful commands for inserting links pointing outside the document.

#### \hyperref

Usage:

This will have the same effect as but will make the text link text a full link, instead. The two can be combined. If the lemma labelled as mainlemma was number 4.1.1 the following example would result in

 We use \hyperref[mainlemma]{lemma \ref*{mainlemma}}. We use lemma 4.1.1.

with the hyperlink as expected. Note the "*" after for avoiding nested hyperlinks.

#### \url

Usage:

It will show the URL using a mono-spaced font and, if you click on it, your browser will be opened pointing at it.

#### \href

Usage:

 \href{}{}

It will show the string description using standard document font but, if you click on it, your browser will be opened pointing at my_url. Here is an example:

 \url{https://www.wikibooks.org}\href{https://www.wikibooks.org}{Wikibooks home}

Both point at the same page, but in the first case the URL will be shown, while in the second case the URL will be hidden. Note that, if you print your document, the link stored using will not be shown anywhere in the document.

### Other possibilities

Apart from linking to websites discussed above, hyperref can be used to provide mailto links, links to local files, and links to anywhere within the PDF output file.

A possible way to insert email links is by

It just shows your email address (so people can know it even if the document is printed on paper) but, if the reader clicks on it, (s)he can easily send you an email. Or, to incorporate the url package's formatting and line breaking abilities into the displayed text, use[2]

When using this form, note that the command is fragile and if the hyperlink is inside of a moving argument, it must be preceeded by a command.

#### Local file

Files can also be linked using the url or the href commands. You simply have to add the string run: at the beginning of the link string:

 \url{run:/path/to/my/file.ext}\href{run:/path/to/my/file.ext}{text displayed}

Following http://tex.stackexchange.com/questions/46488/link-to-local-pdf-file the version with does not always work, but does.

It is possible to use relative paths to link documents near the location of your current document; in order to do so, use the standard Unix-like notation ( is the current directory, is the previous directory, etc.)

It is also possible to create an anchor anywhere in the document (with or without caption) and to link to it. To create an anchor, use:

 \hypertarget{label}{target caption}

and to link to it, use:

where the target caption and link caption are the text that is displayed at the target location and link location respectively.

Note also that if you put a hypertarget, when clicking a link to that hypertarget, it may actually direct to the line after the hypertarget, which is not desirable. Therefore if this occurs, you can report the bug and refer to here for a solution.

## Customization

The standard settings should be fine for most users, but if you want to change something, that is also possible. There are several variables and two methods to pass those to the package. Options can be passed as an argument of the package when it is loaded (the standard way packages work), or the command can be used as follows:

 \hypersetup{ [, ...]}

you can pass as many options as you want; separate them with a comma. Options have to be in the form:

exactly the same format has to be used if you pass those options to the package while loading it, like this:

 \usepackage[]{hyperref}

Here is a list of the possible variables you can change (for the complete list, see the official documentation). The default values are written in an upright font:

Checkout 3.8 Big list at hyperref-manual at tug.org

variablevaluescomment
show or hide the bookmarks bar when displaying the document
allows to use characters of non-Latin based languages in Acrobat’s bookmarks
set the style of the border around a link. The first two parameters (RadiusH, RadiusV) have no effect in most pdf viewers. Width defines the thickness of the border. Dash-Pattern is a series of numbers separated by space and enclosed by box-brackets. It is an optional parameter to specify the length of each line & gap in the dash pattern. For example, {0 0 0.5 [3 3]} is supposed to draw a square box (no rounded corners) of width 0.5 and a dash pattern with a dash of length 3 followed by a gap of length 3. There is no uniformity in whether/how different pdf viewers render the dash pattern.
show or hide Acrobat’s toolbar
resize document window to fit document size
fit the width of the page to the window
define the title that gets displayed in the "Document Info" window of Acrobat
the name of the PDF’s author, it works like the one above
subject of the document, it works like the one above
creator of the document, it works like the one above
producer of the document, it works like the one above
list of keywords, separated by commas, example below
define if a new PDF window should get opened when a link leads out of the current document. NB: This option is ignored if the link leads to an http/https address.
activate back references inside bibliography. Must be specified as part of the \usepackage{} statement.
surround the links by color frames () or colors the text of the links (). The color of these links can be configured using the following options (default colors are shown):
hide links (removing color and border)
color of internal links (sections, pages, etc.)
color of URL links (mail, web)
color of frame around internal links (if )
color of frame around citations
color of frame around URL links

Please note, that explicit RGB specification is only allowed for the border colors (like linkbordercolor etc.), while the others may only assigned to named colors (which you can define your own, see Colors). In order to speed up your customization process, here is a list with the variables with their default value. Copy it in your document and make the changes you want. Next to the variables, there is a short explanations of their meaning:

If you don't need such a high customization, here are some smaller but useful examples. When creating PDFs destined for printing, colored links are not a good thing as they end up in gray in the final output, making it difficult to read. You can use color frames, which are not printed:

When you just want to provide information for the Document Info section of the PDF file, as well as enabling back references inside bibliography:

 \usepackage[pdfauthor={Author's name},% pdftitle={Document Title},% pagebackref=true,% pdftex]{hyperref}

By default, URLs are printed using mono-spaced fonts. If you don't like it and you want them to be printed with the same style of the rest of the text, you can use this:

## Troubleshooting

### Problems with Links and Equations 1

Messages like the following

! pdfTeX warning (ext4): destination with the same identifier (name{ equation.1.7.7.30}) has been already used, duplicate ignored

appear, when you have made something like

 \begin{eqnarray}a=b\nonumber\end{eqnarray}

The error disappears, if you use instead this form:

 \begin{eqnarray*}a=b\end{eqnarray*}

Beware that the shown line number is often completely different from the erroneous line.

Possible solution: Place the amsmath package before the hyperref package.

### Problems with Links and Equations 2

Messages like the following

! Runaway argument? {\@firstoffive }\fi ), Some text from your document here (\ref {re\ETC. Latex Error: Paragraph ended before \Hy@setref@link was complete.

appear when you use inside an environment.

 \AtBeginDocument{\let\textlabel\label}

Note: The same error appears if you use a colon "" as part of a label, i.e. . Replacing that will help.

### Problems with Links and Pages

Messages like the following:

! pdfTeX warning (ext4): destination with the same identifier (name{page.1}) has been already used, duplicate ignored

appear when a counter gets reinitialized, for example by using the command provided by the book document class. It resets the page number counter to 1 prior to the first chapter of the book. But as the preface of the book also has a page number 1 all links to "page 1" would not be unique anymore, hence the notice that "duplicate has been ignored." The counter measure consists of putting into the hyperref options. This unfortunately only helps with the page counter. An even more radical solution is to use the option , but this will cause the page links in the index to stop working.

The best solution is to give each page a unique name by using the command:

 \pagenumbering{alph}% a, b, c, ... ... titlepage, other front matter ... \pagenumbering{roman}% i, ii, iii, iv, ... ... table of contents, table of figures, ... \pagenumbering{arabic}% 1, 2, 3, 4, ... ... beginning of the main matter (chapter 1) ...

Another solution is to use before the command , which will give the title page the label page.a. Since the page number is suppressed, it won't make a difference to the output.

By changing the page numbering every time before the counter is reset, each page gets a unique name. In this case, the pages would be numbered a, b, c, i, ii, iii, iv, v, 1, 2, 3, 4, 5, ...

If you don't want the page numbers to be visible (for example, during the front matter part), use . The important point is that although the numbers are not visible, each page will have a unique name.

Another more flexible approach is to set the counter to something negative:

 \setcounter{page}{-100} ... titlepage, other front matter ... \pagenumbering{roman}% i, ii, iii, iv, ... ... table of contents, table of figures, ... \pagenumbering{arabic}% 1, 2, 3, 4, ... ... beginning of the main matter (chapter 1) ...

which will give the first pages a unique negative number.

The problem can also occur with the package: because each algorithm uses the same line-numbering scheme, the line identifiers for the second and follow-on algorithms will be duplicates of the first.

The problem occurs with equation identifiers if you use on every line of an eqnarray environment. In this case, use the *'ed form instead, e.g. (which is an unnumbered equation array), and remove the now unnecessary commands.

If your url's are too long and running off of the page, try using the package to split the url over multiple lines. This is especially important in a multicolumn environment where the line width is greatly shortened.

### Problems with bookmarks

The text displayed by bookmarks does not always look like you expect it to look. Because bookmarks are "just text", much fewer characters are available for bookmarks than for normal LaTeX text. Hyperref will normally notice such problems and put up a warning:

Package hyperref Warning: Token not allowed in a PDFDocEncoded string:

You can now work around this problem by providing a text string for the bookmarks, which replaces the offending text:

 \texorpdfstring{''TEX text''}{''Bookmark Text''}

Math expressions are a prime candidate for this kind of problem:

 \section{\texorpdfstring{$E=mc^2$}{E=mc2}}

which turns to in the bookmark area. Color changes also do not travel well into bookmarks:

 \section{\textcolor{red}{Red !}}

produces the string "redRed!". The command gets ignored but its argument (red) gets printed. If you use:

 \section{\texorpdfstring{\textcolor{red}{Red !}}{Red\ !}}

the result will be much more legible.

If you write your document in unicode and use the unicode option for the hyperref package you can use unicode characters in bookmarks. This will give you a much larger selection of characters to pick from when using .

### Problems with tables and figures

The links created by hyperref point to the label created within the float environment, which, as previously described, must always be set after the caption. Since the caption is usually below a figure or table, the figure or table itself will not be visible upon clicking the link[4]. A workaround exists by using the package hypcap[2] with:

If you use the wrapfig package[5] mentioned in the "Wrapping text around figures" section of the "Floats, Figures and Captions" chapter, or other similar packages that define their own environments, you will need to manually include in those environments, e.g.:

 \begin{wrapfigure}{R}{0.5\textwidth}\capstart\begin{center}\includegraphics[width=0.48\textwidth]{filename}\end{center}\caption{\label{labelname}a figure}\end{wrapfigure}

### Problems with long caption and \listoffigures or long title

There is an issue when using with hyperref for long captions or long titles. This happens when the captions (or the titles) are longer than the page width (about 7-9 words depending on your settings). To fix this, you need to use the option breaklinks when first declaring:

This will then cause the links in the to word wrap properly.

### Problems with already existing .toc, .lof and similar files

The format of some of the auxilliary files generated by latex changes when you include the hyperref package. One can therefore encounter errors like

! Argument of \Hy@setref@link has an extra }.

when the document is typeset with hyperref for the first time and these files already exist. The solution to the problem is to delete all the files that latex uses to get references right and typeset again.

### Problems with footnotes and special characters

See the relevant section.

### Problems with Beamer

Using the command

 \hyperref[some_label]{some text}

is broken when pointed at a label. Instead of sending the user to the desired label, upon clicking the user will be sent to the first frame. A simple work around exists; instead of using

 \phantomsection\label{some_label}

 \hypertarget{some_label}{}

and reference it with

### Problems with draft mode

The hyperlinks can be re-enabled by using the "final=true" option in the following initialization of the hyperref package, just after the package was included:

 \usepackage{hyperref}\hypersetup{final=true}

A good source of further options for the hyperref package can be found here [6].

## Notes and References

Adding colors to your text is supported by the package (supersedes package color). 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.

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

The package has some options to get more predefined colors, which should be added globally. 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.

If you need more colors, then you may also want to look at the x11names option. This offers more than 300 colors.

## 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 .

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 and is the same as that between and , you can use the one you prefer. The environment allows the text to run over multiple lines and other text environments whereas the text in 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}

This above syntax may result in an error if you are using beamer with tikz. To go around it, include usenames and dvipsnames options when defining the document class.

 \documentclass[usenames,dvipsnames]{beamer}
NameColor ColorName
Apricot   Aquamarine
Bittersweet   Black
Blue   BlueGreen
BlueViolet   BrickRed
Brown   BurntOrange
Cerulean   CornflowerBlue
Cyan   Dandelion
DarkOrchid   Emerald
ForestGreen   Fuchsia
Goldenrod   Gray
Green   GreenYellow
JungleGreen   Lavender
LimeGreen   Magenta
Mahogany   Maroon
Melon   MidnightBlue
Mulberry   NavyBlue
OliveGreen   Orange
OrangeRed   Orchid
Peach   Periwinkle
PineGreen   Plum
ProcessBlue   Purple
RawSienna   Red
RedOrange   RedViolet
Rhodamine   RoyalBlue
RoyalPurple   RubineRed
Salmon   SeaGreen
Sepia   SkyBlue
SpringGreen   Tan
TealBlue   Thistle
Turquoise   Violet
VioletRed   White
WildStrawberry   Yellow
YellowGreen   YellowOrange

## 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):

ModelDescriptionColor SpecificationExample
(0-1)
Just one number between 0 (black) and 1 (white), so 0.95 will be very light gray, 0.30 will be dark gray.
Red, Green, Blue
(0-1)
Three numbers given in the form red,green,blue; the quantity of each color is represented with a number between 0 and 1.
Red, Green, Blue
(0-255)
Three numbers given in the form red,green,blue; the quantity of each color is represented with a number between 0 and 255.
Red, Green, Blue
(00-FF)
Six hexadecimal numbers given in the form RRGGBB; similar to what is used in HTML.
Cyan, Magenta, Yellow, Black
(0-1)
Four numbers given in the form cyan,magenta,yellow,black; the quantity of each color is represented with a number between 0 and 1.

### 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, and 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:

### 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 (CMYK and CIELAB). They are defined with, say:

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

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