PyPlot - Tricky axis color and labeling issues - date

Question

I am fairly new to Matplotlib. This idea behind this figure is to graph temperature highs and lows. I've run into trouble with the xaxis and right yaxis.
For the xaxis, the color of the font doesn't want to change even though I call tick_params(labelcolor='#b6b6b6'). Also, the dates should only span from Jan - Dec. For unknown reasons, Matplotlib is prepending an extra Dec and appending an extra Jan, causing the text to flow outside of the graph's spine bounds. I want to remove these extra months.
For the right yaxis, I'm not sure I understand the use of subplots properly. I want to convert the ˚C temperatures in the left yaxis to ˚F and use the converted temps for the secondary yaxis.
Here's some code to reproduce something similar to what I've got.
import numpy as np
import pandas as pd
import matplotlib as mpl
import matplotlib.pyplot as plt
import matplotlib.dates as dates
import matplotlib.ticker as ticker
# generate some data to plot
highs = np.linspace(0, 40, 365) # these numbers will escalate instead of fluctuate, but the problem with the axes will still be the same.
lows = np.linspace(-40, 0, 365)
date_rng = pd.date_range('1/1/2015', '12/31/2015', freq='D')
data = {'highs': highs, 'lows': lows}
to_plot = pd.DataFrame(data, index=date_rng)
fig, ax = plt.subplots()
# plot the basic data
lines = ax.plot(date_rng, to_plot['lows'], '-',
date_rng, to_plot['highs'], '-')
# get the axes reference
ax1 = plt.gca()
# fill in between the lines
ax1.fill_between(date_rng,
to_plot['lows'], to_plot['highs'],
facecolor='#b6b6b6', # gradient fillbetween
alpha=.2)
# set the xaxis to only 12 months and space the names.
ax1.xaxis.set_major_locator(dates.MonthLocator())
ax1.xaxis.set_minor_locator(dates.MonthLocator(bymonthday=15, interval=1))
ax1.xaxis.set_major_formatter(ticker.NullFormatter())
ax1.xaxis.set_minor_formatter(dates.DateFormatter('%b'))
for tick in ax1.xaxis.get_minor_ticks():
tick.tick1line.set_markersize(0)
tick.tick2line.set_markersize(0)
tick.label1.set_horizontalalignment('center')
# add a right y axis and set all yaxis properties
ax1.set_ylim([-50, 50])
# change the color and sizes scheme
info_colors = '#b6b6b6'
bold_colors = '#777777'
# graph lines
ax1.lines[0].set_color('#e93c00') # top redish orange
ax1.lines[1].set_color('#009ae9') # btm blue
plt.setp(lines, lw=.8, alpha=1)
# spines
ax.spines['top'].set_visible(False)
for pos in ['bottom', 'right', 'left']:
ax.spines[pos].set_edgecolor(info_colors)
# set the title
plt.title('Record Temps, 2005-15: Ann Arbour, MI', fontsize=10, color=bold_colors)
# ticks
ax1.tick_params(axis='both', color=info_colors, labelcolor=info_colors, length=5, direction='out', pad=7, labelsize=8)
# add a legend and edit its properties
leg = plt.legend(['Highs','Lows'], frameon=False, loc=0, fontsize='small')
for text in leg.get_texts():
text.set_color(info_colors)
plt.ylabel('˚C', color=info_colors)
# set extra yaxis label
ax2 = ax.twinx()
ax2.set_ylabel('˚F', color=info_colors)
ax2.tick_params('y', colors=info_colors)

Answer 1

To change the color of the minor labels, put the following code after ax1.xaxis.set_minor_formatter(dates.DateFormatter('%b')):
ax1.xaxis.set_tick_params(which='minor', colors=info_colors)