I recently upgraded to the binary for Windows version
> 0.60.2 and found that the plus (+) symbol always plots in
> black even though a color is specified. My fix was to
> change the parameter lines.markeredgecolor to the color I
> wanted using the rc() command and then to revert to the
> default using rcdefaults(). This works ok for me but I
> thought you might want to know in case it's a bug.
Yes, this is a bug, sort of. '+' is a marker. In the current
matplotlib, the colorarg only sets the marker face color but not the
edge color. For circles and the like, this is normally not a
problem. But for '+' it makes no sense.
In the next release, color args will affect both the edge and face
colors, and you can override this by providing a kwarg, eg
>>> plot(range(10), 'r+') # red plusses
>>> plot(range(10), 'ro') # red circles, edge and face
>>> plot(range(10), 'ro', markeredgecolor='k') # red face, black edge
Thanks for letting me know.