CODE EXAMPLE FOR PYTHON

plt.text background alpha

plt_text = plt.text(
	0.5,  # x
    0.5,  # y
    'your text',  # text
    fontsize=30
)
plt_text.set_bbox(dict(
	facecolor='red',  # background color
    alpha=0.5,  # background alpha
    edgecolor='red'  # border color
))