cellcolor affects horizontal alignment in table

Question

I have a table and I want to highlight some cells with color with \cellcolor.

However the horizontal alignment is distorted, as you can see in the image.

Can this be corrected with the current approach?

I didn't find any relevant information and a radically new approach would be preferably avoided.

I found only the workaround of adding a(n extra) ~ in the beginning of the non-highlighted cells of the same column. It works, but this is a workaround.

\documentclass{article}

\usepackage{array}
\usepackage{hhline}
\usepackage[usenames,dvipsnames,svgnames,table]{xcolor}

\begin{document}
\begin{table}[h]
    \footnotesize 
    \begin{center}
        \caption{blah}
        \label{fig:QResults}
        \setlength{\tabcolsep}{1pt}
        \begin{tabular}{|l|c|c|}                                                       \hhline{-|~|-}
            \multicolumn{1}{|c|}{~~Features~~} & \multicolumn{1}{ c|}{} & ~~error~~ \\ \hhline{-|~|-}
            \noalign{\smallskip}                                                       \hhline{-|~|-}
            \cellcolor[gray]{0.8} {~~feat1~~} & {} & \cellcolor[gray]{0.8} {$1.49$} \\ \hhline{-|~|-}
                                  {~~feat2~~} & {} &                       {$4.86$} \\ \hhline{-|~|-}
                                  {~~feat3~~} & {} &                       {$4.67$} \\ \hhline{-|~|-}
        \end{tabular}
    \end{center}
\end{table}
\end{document}

Answer 1

You should get rid of the space between cellcolor and the cell value:

\cellcolor[gray]{0.8}~~feat1~~ & {} & \cellcolor[gray]{0.8}{$1.49$} \\ \hhline{-|~|-}

This works.