from matplotlib import pyplot as plt

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True
plt.rcParams['axes.linewidth'] = 5

ax = plt.axes()

ax.spines['bottom'].set_color('yellow')
ax.spines['top'].set_color('red')
ax.spines['right'].set_color('black')
ax.spines['left'].set_color('blue')

plt.show()