faceted color=none has no effect if fill or opacity is used in surface plots

[FranzAtGithub]

Hi there,

I feel like faceted color=none is broken in some situations.

Consider the code:

\documentclass{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}


\begin{document}

\begin{tikzpicture}
    \begin{axis}

        % faceted color=none has no effect
        \addplot3 [
        domain y=0:2,
        domain=-2:2,
        surf,
        faceted color=none,
        fill=pink,
        opacity=0.2,
        samples y=20,
        samples=20,
        ] {0};

        % no use of faceted color
        % color is based on "function value"
        \addplot3 [
        domain y=0:2,
        domain=-2:2,
        surf,
        fill=pink,
        opacity=0.2,
        samples y=20,
        samples=20,
        ] {2};

        % removing only opacity
        % faceted color=none has no effect
        \addplot3 [
        domain y=0:2,
        domain=-2:2,
        surf,
        faceted color=none,
        fill=pink,
        samples y=20,
        samples=20,
        ] {4};

        % removing only fill
        % faceted color=none has no effect
        \addplot3 [
        domain y=0:2,
        domain=-2:2,
        surf,
        faceted color=none,
        opacity=0.2,
        samples y=20,
        samples=20,
        ] {6};

        % removing opacity and fill
        % only here does faceted color=none work
        \addplot3 [
        domain y=0:2,
        domain=-2:2,
        surf,
        faceted color=none,
        samples y=20,
        samples=20,
        ] {8};

    \end{axis}
\end{tikzpicture}

\end{document}

The option faceted color=none seems only to work when the options fill and opacity are not used.
Is there a work-around that I could use?

There is a related post on tex.stackexchange about this.