NS seems to always print colored or shaded table cells. However, you can
control whether it prints the background of the page as it appears on screen
or prints a blank background regardless of the on-screen background. Click
on the "File" menu, then choose "Page Setup", then check or uncheck "Print
backgrounds" in the "Page Options" section.
In IE, a similar option called "Print background colors and images" affects
not only page backgrounds, but table cell shading. If this option is turned
off, shaded table cells will print as if they had no shading. This may be
useful if the shading makes the text in the table cell illegible on when
printed. To turn this option on or off, click on the "Tools" menu, then on "Internet
options", then on the "Advanced" tab, then scroll down to find the "Printing" heading
(it has a small printer icon on the left), and check or uncheck the "Print
background colors and images" box.
(Note that in NS but not IE can print shaded table cells without printing
a colored or graphical background, and IE but not NS can print table cells
without their shading.)