How to create an array of styles and use it?

Question

I want to create an array of custom defined styles and afterwards use these styles by getting them by index.

My approach so far, which isn't working:

1. Defining some styles:

   \pgfplotsset{
       redline/.style={
           red
       },
       blueline/.style={
           blue
       }
   }
   

2. Defining an array with the styles:

   \def\mystylesarray{
       {redline},
       {blueline}
   }
   

3. Using them in a plot:

   \begin{tikzpicture}
       \begin{axis}
           \addplot[\mystylesarray[0]] {x};
           \addplot[\mystylesarray[1]] {x^2};
       \end{axis}
   \end{tikzpicture}
   

I also tried the following:

In step 2. I tried \newcommand instead of \def and using two braces around the array implementation. In step 3. I tried curly braces and normal braces. All sorts of combinations and looking for an answer online didn't bring up a solution.

Your help is appreciated.

---

MWE:

\documentclass{scrreprt}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\pgfplotsset{
    redline/.style={
        red
    },
    blueline/.style={
        blue
    }
}
\def\mystylesarray{
    {redline},
    {blueline}
}

\begin{document}
    \begin{tikzpicture}
    \begin{axis}
    \addplot[\mystylesarray{0}] {x};
    \addplot[\mystylesarray{1}] {x^2};
    \end{axis}
    \end{tikzpicture}
\end{document}