Packages multirow and columncolor give ugly stripes

Question

I have two problems on one slide. This is an example:

\documentclass{beamer}

\usepackage{graphicx}
\usepackage{tabulary}
\usepackage{colortbl}
\usepackage{multirow}
\usepackage{xcolor}
\usepackage{setspace}

% DEFINE COLORS
\xdefinecolor{lGrey}{RGB}{238,238,238}
\xdefinecolor{dGrey}{RGB}{64,64,64}
\xdefinecolor{myRed}{RGB}{164,30,55}

\title{Example}
\author{PM}
\date{\today}

\begin{document}

\frame{\titlepage}

\frame
{
    \frametitle{Title}
    \begin{center}
    {\scriptsize{
    \begin{tabular}{>{\columncolor{myRed}}ccc}
        \rowcolor{myRed}
            & \color{lGrey} Metaphor & \color{lGrey} Instrument \\
            \cellcolor{myRed} & Something, & Something else \\
            \cellcolor{myRed}\multirow{-2}{*}{\color{lGrey} My stuff}
                & And more & (and paper and pen) \\
            \cellcolor{myRed} & Hand & Leg, \\
            \cellcolor{myRed}\multirow{-2}{*}{\color{lGrey} Other stuffs}
                & thoughts & data \\
    \end{tabular}
    }}
\end{center}
}

\end{document}

The problem is that I am getting ugly stripes for multirow cells: they should be red, but between one can see white line. How can I eliminate this?

Another issue, if I may, is that table is not really centered. It is more to the right.