One more thing to check.
File | Page Setup and on the [Sheet] tab make sure that the box next to
"Black and White" is cleared. If it has a check in it, the page will print
in black and white even though it shows colors on screen.
Another oddity - if you have multiple printers attached and the default
printer is a black and white only printer (perhaps a b/w laser), then if that
printer is chosen even the Print Preview will appear in black and white. To
preview in color, choose a color capable printer also.