Making footnote marks in beamer use the surrounding color

Question

As is probably well known, footnote marks in beamer are colored using the footnote mark beamer-color, which seems to default to black, so that footnote marks are black even when the surrounding text has a different color. Example:

\documentclass{beamer}
\begin{document}
 \begin{frame}
  \color{red}some text\footnote{test} and some more text

  \color{green}some text\footnote{test} and some more text
 \end{frame}
\end{document}

which produces

What would be the cleanest way to change this so that footnote marks take on the color of the surrounding text? In this case I'd like the ¹ in the main text to be red and the ² in the next line to be blue, but without explicitly having to write those colors. The ¹ and ² in the footnotes themselves should likewise take on the color of footnote text, which in this case is black.

In particular, I'm not looking for this:

  {\setbeamercolor{footnote mark}{fg=red}
   \color{red}some text\footnote{test} and some more text
  }

because that would also change the color of the mark in the footnote, and also because I have situations in which it's not so easy to figure out what color the surrounding text actually is.

Undefining the color as suggested in this other question, with

  \setbeamercolor{footnote mark}{use=,parent=,fg=,bg=}

doesn't work either.

What's the cleanest way to make this happen?

An ideal solution would make footnote marks take on the surrounding text color by default but still respect \setbeamercolor{footnote mark}{...} if I set it explicitly. But for my current project, it will be acceptable if setting the footnote mark beamer-color has no effect.

Answer 1

Colour setting to . takes exactly this into effect:

\documentclass{beamer}% http://ctan.org/pkg/beamer
\setbeamercolor{footnote mark}{fg=.}
\begin{document}
\begin{frame}
  \color{red}some text\footnote{test} and some more text

  \color{green}some text\footnote{test} and some more text
\end{frame}
\end{document}

This is discussed in section 2.6.3 Using the current color (p 23) of the xcolor package documentation.