When I tried to add color to the cells to differentiate concavity points up from down, the text in the cells moved down versus the cells with no color added. What can I do to keep all cells text at the same level?
\documentclass[12pt,table]{report}
\usepackage{xcolor}
\usepackage{mathtools}
\usepackage{longtable,tabu}
\setlength{\extrarowheight}{4pt}
\begin{document}
\bigbreak
\begin{longtabu}{
|p{\dimexpr.25\linewidth-2\tabcolsep-1.3333\arrayrulewidth}
|p{\dimexpr.15\linewidth-2\tabcolsep-1.3333\arrayrulewidth}
|p{\dimexpr.25\linewidth-2\tabcolsep-1.3333\arrayrulewidth}
|} %\textwidth
\hline
\centering \boldmath $\text{Lable on Sketch}$ & \centering \boldmath $x$ & \centering \textbf{Concavity} \tabularnewline\hline
\centering $x_{0}$ & \centering $0$ & \centering \color{red}Concave up\\\hline
\centering $x_{0}$ & \centering $0$ & \centering Concave up\\\hline
\end{longtabu}
\end{document}
\textcolor{red}{Concave up}
.