How to make 3-D axes/grid more visible?

I've been using Axes3D to make plots and I like the output very much --
with the one exception being the faintness of the 3-D grid that is put
in the background. The light gray used is quite difficult to see. Is
there some way to specify the color of the grid and/or background? I'd
be satisfied with having the grid lines darker. I've been looking
through the file under mpl_toolkits/mplot3d but haven't
figured it out yet.

By the way, anyone looking to specify an initial non-default orientation
for the grid, I discovered that you can do this when instantiating your
Axes3D object this way:
ax = Axes3D(fig,elev=e,azim=a)
where e and a are the elevation about the x-axis and azimuthal rotation
about the z-axis (both in degrees). 0 azimuthal rotation has the y-z
plane in the plane of the screen; azim. rotation is defined as clockwise
as viewed from above.