Use the fill function to make shaded regions of any color tint. Here is an example.
1
2 from pylab import *
3
4 x = arange(10)
5 y = x
6
7 # Plot junk and then a filled region
8 plot(x, y)
9
10 # Make a blue box that is somewhat see-through
11 # and has a red border.
12 # WARNING: alpha doesn't work in postscript output....
13 fill([3,4,4,3], [2,2,4,4], 'b', alpha=0.2, edgecolor='r')
