如何使用pyplot仅更改一个条形图的颜色？

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]
y = [10, 15, 7, 12, 9]

plt.bar(x, y)

plt.bar(x[2], y[2], color='red')

plt.show()

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]
y = [10, 15, 7, 12, 9]

plt.bar(x, y)
plt.bar(x[2], y[2], color='red')

plt.show()