import matplotlib,numpy
import pylab

#Generate some example data... From http://matplotlib.sourceforge.net/examples/pylab_examples/contourf_demo.html
delta = 0.025
x = numpy.arange(-3.0, 3.0, delta)
y = numpy.arange(-2.0, 2.0, delta)
X, Y = numpy.meshgrid(x, y)
Z1 = pylab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
Z2 = pylab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
# difference of Gaussians
Z = 100.0 * (Z2 - Z1)
#This is the random colormap bit
random_colormap = matplotlib.colors.ListedColormap ( numpy.random.rand ( 10,3))
#Does it work?
pylab.imshow ( Z, cmap = random_colormap)
pylab.colorbar()
pylab.show()