Bar and box plots always use the 'default' matplotlib colormap, even the style is changed
I set the matplotlib style to "fivethirtyeight", which changes many settings in the axes, colors, etc.

This is what I get when doing a simple line plot:

```
pd.DataFrame(dict(a=[1, 2, 3], b=[5, 10, 2])).plot.line()
```

![plot1](https://cloud.githubusercontent.com/assets/1626936/12292185/be56e276-b9eb-11e5-8c78-d412114a53cd.png)

The style matches what I was expecting.

(hist, area and other type of plots I tried work as well)

But when I want to get a bar plot, I get this:

```
pd.DataFrame(dict(a=[1, 2, 3], b=[5, 10, 2])).plot.bar()
```

![plot2](https://cloud.githubusercontent.com/assets/1626936/12292188/c1733e1e-b9eb-11e5-9e90-48f8bb65588e.png)

Most elements of the style seem to be here, but the colors are the default matplotlib ones, not the ones in "fivethirtyeight" (and the same goes with a boxplot)

![plot3](https://cloud.githubusercontent.com/assets/1626936/12292249/1b43981c-b9ec-11e5-8656-a1c6a147a62e.png)

Any clue about what might be causing this?

These are the lines I used to style my plots:

```
import matplotlib.pyplot as plt
import matplotlib
matplotlib.style.use('fivethirtyeight')

%matplotlib inline

COLORS = [(0.3333333333333333, 0.6588235294117647, 0.40784313725490196),
 (0.2980392156862745, 0.4470588235294118, 0.6901960784313725),
 (0.7686274509803922, 0.3058823529411765, 0.3215686274509804),
 (0.5058823529411764, 0.4470588235294118, 0.6980392156862745),
 (0.8, 0.7254901960784313, 0.4549019607843137),
 (0.39215686274509803, 0.7098039215686275, 0.803921568627451),
 (0.33999999999999997, 0.86, 0.57920000000000016)]

plt.rcParams['figure.figsize'] = (14.0, 7.0)
plt.rcParams['axes.prop_cycle'] = plt.cycler('color', COLORS)
```
