aligncolor
regarding this documentation
ftp://tug.org/tex-archive/info/math/voss/mathCol/mathCol.pdf
it should be easy to change the color of an align environment like this:
\documentclass{article}
\usepackage{color,amsmath}
\begin{document}
\begin{align}\color{red}
x &= 1\\
y &= 2
\end{align}
\end{document}
But all that changes to red is the first entry, i.e. the x.
I use MiKTeX 2.8 on Windows XP.
Any ideas?
Knuth in the TeXBook gave an example of "poor man's bold," (The TeXbook, p. 386) which can be typeset obtained by overprinting the normal weight symbol with slight offsets.
As he says:
The results are somewhat fuzzy, and they certainly are no match for the real thing if it's available; but poor man's bold is better than nothing, and once in a while you can get away with it.
Here, one can use a similar technique and the code is shown below:
\documentclass{article}
\usepackage{graphicx,xcolor}
\usepackage{amsmath}
\def\PoorManContour#1#2#3{\leavevmode
\setbox0=\hbox{{#1}}%
\color{#3}\kern-.002em\copy0\kern-\wd0
\color{#3}\raise-.04em\copy0\kern-\wd0
\color{#3}\lower.04em\copy0\kern-\wd0
\color{#3}\raise0.04em\copy0\kern-\wd0
\color{#2}\raise-.012em\copy0\kern-\wd0
\color{#2}\kern.06em\copy0\kern-\wd0
\color{blue}\kern-.020em\lower.003em\box0
}
\begin{document}
\colorbox{gray!5}{\scalebox{5}{\PoorManContour{$\sqrt{\dfrac{A^3_i}{B^2}}$}{gray!60}{gray!60}}}
\end{document}
To achieve the best results possible one has to kern in small steps for possibly twenty steps or so. For simplicity, I have not done that. In the final version, you need to adjust the colors to suit, possibly changing the shading to white.
Edit
After reading Jan's comment below I read the manual and true, as the commenter said the easiest way to achieve what the OP wanted is to include the package without an option i.e., \usepackage{contour}. Helps to RFM!
These option clashes happen when a package is requested to be loaded on two different positions, like by you and inside another package, but with different options. The package is loaded by the first \usepackage (or its twin \RequirePackage); it isn't loaded again when it is requested again. It simply can't be loaded a second time. Therefore the new options can be activated and previous options might conflict with the second usage. So LaTeX creates an error to report this issue to you.
The way to fix this is to declare the options beforehand using \PassOptionsToPackage{<options>}{<package>}. Then they are used wherever the package is loaded.
\documentclass{article}
\usepackage{ifpdf}
\ifpdf
\PassOptionsToPackage{pdftex,usenames,dvipsnames}{color}
\usepackage[T1]{fontenc}
\usepackage{libertine} % most likely loads 'color' itself
%\usepackage{lmodern} % doesn't load 'color'
\usepackage{color}
\usepackage[pdftex]{graphicx}
\else
%\bye
\fi
\begin{document}
Hello, world!
\end{document}
I can't test it by myself, because I don't have the libertine package installed.
I don't think you need to set pdftex manually. Normally packages do a good job recognizing the driver by themselves. Also you might want to use the extended xcolor package instead of color.
Best Answer
Each cell within the
alignenvironment forms a group, localizing the extent of the colour change. If you wrap the colour change around the outside ofalign, it spans across the internal cells:You'll notice that this sets even the equation numbers in
\color{red}. This is easily fixed by adding the following to your preamble:The above
etoolbox-patch inserts ablackcolour-change around the number-printing mechanism\place@tag:For individual colour modifications to each cell/component of the line, insert
\color{<colour>}in the respective cells you want to use colour<colour>.