Two ordinates - gray tick lines overlay black axis line

Question

I want to plot two data series with different y-coordinates over the same x. Therefore a second ordinate is drawn with a second axis environment. When I now limit the range to be drawn, the gray tick lines of the second plot overlay the black axis line of the first one. Is there a way to adjust this or to change the color of the tick lines to black (workaround, but would be okay for me). See the following minimal code sample and the cropped image below.

\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{figure}
    \begin{tikzpicture}
    \begin{axis}[
    axis x line*=bottom,
    axis y line*=left,
    xmin=0,
    xmax=1,
    ymin=0,
    ymax=1
    ]
    \end{axis}
    \begin{axis}[
    axis x line*=top,
    axis y line*=right,
    xmin=0,
    xmax=1,
    ymin=0,
    ymax=1
    ]
    \end{axis}
    \end{tikzpicture}
\end{figure}
\end{document}

Answer 1

Use the option every tick/.style={black} to control tick color. You can add as many specifications as you want, e.g., color, line width, ..etc.

\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{figure}
    \begin{tikzpicture}
    \begin{axis}[
    axis x line*=bottom,
    axis y line*=left,
    xmin=0,
    xmax=1,
    ymin=0,
    ymax=1
    ]
    \end{axis}
    \begin{axis}[
    axis x line*=top,
    axis y line*=right,
    every tick/.style={black},
    xmin=0,
    xmax=1,
    ymin=0,
    ymax=1
    ]
    \end{axis}
    \end{tikzpicture}
\end{figure}
\end{document}

Ultra zoomed picture: