I'm having a few issues with creating a legend in the caption of an image. I've made a lot of graphs using matlab2tikz and I've externalised them to reduce my compiling time and memory usage. Consequently, I can't then use any \labels in the code. So I'm making a TikZ plot immediately below it and using those line styles in the caption. A MWE is displayed below:
\begin{tikzpicture}
\begin{axis}[hide axis]
\addplot [color=red,solid,forget plot]
(0,0);\label{hwplot1}
\addplot[color=brown,solid,mark=o,mark options={solid},forget plot]
(0,0);\label{Blomhoff}
\end{axis}
\end{tikzpicture}
I then call the label in the caption and everything works a ok. The issue that arises is that I get a brown dot at what TikZ defines at (0,0), which is the mark, and I can't find a way of getting rid of this. Is there a way I can do this? Or an alternative method of putting the legend in the caption that allows for externalization?
Thanks in advance

externallibrary allows references to labels in external files -- but not together with the default system call. Do you use windows or unix? Unix users can typically usemaketo get this without any problems. – Christian Feuersänger Oct 20 '14 at 18:38