x_min, x_max = X_t[:, 0].min()-2, X_t[:, 0].max() + 2
y_min, y_max = X_t[:, 1].min()-2, X_t[:, 1].max() + 2

xx, yy = np.meshgrid(np.arange(x_min,x_max,0.1),
                  np.arange(y_min, y_max,0.1))

Z = gas_pca.predict(np.c_[xx.ravel(), yy.ravel()])
Z = Z.reshape(xx.shape)

fig, ax = plt.subplots()
ax.contourf(xx, yy, Z, colors = ('#75bbfd', '#fff9d0', '#ffb07c', '#c2ff89') )