# coloring single cell in smallmatrix

I'm trying to color a single cell in smallmatrix, but it seems to me that the \cellcolor doesn't work in smallmatrix:

\documentclass{article}
\usepackage{amsmath} %smallmatrix
\usepackage[table]{xcolor} %cellcolor
\begin{document}
$\left(\begin{array}{cc} \cellcolor{gray}1&2 \end{array}\right) \quad \left(\begin{smallmatrix} \cellcolor{gray}1&2 \end{smallmatrix}\right)$
\end{document}


You can see that the array is colored as desired while in smallmatrix \cellcolor doesn't do anything.

Does anyone know how to do color cells in smallmatrix?

You need to use the \colorbox macro. And, since the \colorbox macro typesets its second argument in text mode (and text style), be sure to encase the second argument in a $\scriptstyle ...$ "wrapper".

$(\begin{smallmatrix} \colorbox{lightgray}{$\scriptstyle 1$}&2 \end{smallmatrix})$


A full MWE: (mininimum working example):

\documentclass{article}
\usepackage{amsmath}       % smallmatrix env.
\usepackage[table]{xcolor} % \cellcolor, \colorbox
\begin{document}

$\left(\begin{array}{cc} \cellcolor{lightgray}1&2 \end{array}\right)$

$(\begin{smallmatrix} \colorbox{lightgray}{$\scriptstyle 1$}&2 \end{smallmatrix})$

\end{document}

• Thanks! A further question: if I want to color an entire row in smallmatrix, I can do it cell-by-cell as you suggested. Is there a \colorbox analogue to \rowcolor? – Chun-Ju Lai Jun 4 '17 at 9:26
• @Chun-JuLai - You may be abusing the entire design philosophy of smallmatrix if you start coloring entire rows. I certainly wouldn't do it. – Mico Jun 4 '17 at 11:51
• You are probably right. I end up using scalebox when there's a need for coloring a row in the matrix. – Chun-Ju Lai Jun 9 '17 at 9:29