matplotlib y axis background color code example
Example: matplotlib background color
fig, ax = plt.subplots()
#to change the inside of the graph
ax.set_facecolor('xkcd:salmon')
ax.set_facecolor((1.0, 0.47, 0.42))
#to change the border color around the back
fig.patch.set_facecolor('xkcd:mint green')