Matplotlib Orange Line
# credit to the Stack Overflow user in the source link
# choose one of these three possibilities
plt.plot(x, z3, '--', color='orange') % String colorspec
plt.plot(x, z3, '--', color='#FFA500') % Hex colorspec
plt.plot(x, z3, '--', color=[1.0, 0.5, 0.25]) % RGB colorspec
wolf-like_hunter