\documentclass[12pt]{article}
\usepackage{amssymb,amsmath,amscd,concmath,amsfonts}
\usepackage{color}
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\begin{document}
\begin{equation*}
  \frac{dh}{dt} = -\frac{a}{A}\sqrt{2gh} {\color{blue} +} \frac{1}{A}q_{in},
  \qquad q_{out} = a\sqrt{2gh}.
\end{equation*}
\end{document}