[BUG] KDE plot and color kwarg

[TomAugspurger]

Not sure if this is a bug here or not.

import pandas as pd
import numpy as np

d = {'noise': np.random.randn(100).cumsum(),
     'trend': np.arange(100)}

df = pd.DataFrame(d)
df['resid'] = pd.ols(y=df.noise, x=df.trend).resid
df['resid'].plot(kind='kde', color='k')

Will give this traceback:

In [14]: Traceback (most recent call last):
      File "/usr/local/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
        draw(artist, renderer, *args, **kwargs)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/figure.py", line 927, in draw
        func(*args)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
        draw(artist, renderer, *args, **kwargs)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/axes.py", line 1999, in draw
        a.draw(renderer)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
        draw(artist, renderer, *args, **kwargs)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/lines.py", line 494, in draw
        gc.set_foreground(self._color)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.py", line 189, in set_foreground
        GraphicsContextBase.set_foreground(self, fg, isRGB)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 878, in set_foreground
        self._rgb = colors.colorConverter.to_rgba(fg)
      File "/usr/local/lib/python2.7/site-packages/matplotlib/colors.py", line 354, in to_rgba
        raise ValueError('to_rgba: Invalid rgba arg "%s"\n%s' % (str(arg), exc))
    ValueError: to_rgba: Invalid rgba arg "['k']"
    need more than 1 value to unpack

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        https://github.com/ipython/ipython/issues
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    You can print a more detailed traceback right now with "%tb", or use "%debug"
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        %config Application.verbose_crash=True

I haven't add a chance to look through the plotting code yet to see if this should work or not, but it seems like it should.

In [14]: pd.__version__
Out[14]: '0.11.0.dev-7d11531'

And this happens in IPython both with and without pylab mode. I've tried with other rgba values and they seem to fail too.

[changhiskhan]

@TomAugspurger can you give it another shot?

[TomAugspurger]

@changhiskhan Works great now. Thanks!