Excel – How to print an Excel Spreadsheet as Grayscale

My wild guess is that you have some weird setting activated in your print dialog that you should change....

1. Click "Print".
2. After the print dialog opens, first select your target printer.
3. Now click the "Advanced" button (lower row, second from left).
4. Play with all the "Output" settings: Color, Screening, Trapping, Transparency Flattener Presets, Color Management.
5. Play with all the "PostScript Options" settings: UnderColor Removal, Black Generation, Halftones,...
6. Play with all the "Color Management" settings.

In the same dialog, you can also enable the "Print as Image" function (to checkbox). Try it.

BTW, what kind of printer is it that you are trying to print this to? (If it is a non-PostScript device, then some of the above mentioned settings will be disabled/grayed-out...)

Update:

I only now noticed from your screenshot, that you're using Adobe Acrobat Professional. In this case you can enable a rather sophisticated output preview:

1. Menu Advanced -> Print Production -> Output Preview...
2. Look at all the possible settings.
3. Pay special attention to the lower pane named "Separations" (if you click on 'Separations' in the "Preview" pane first...).
   • Enable a Simulation Profile that matches your printer.
   • In case you're a using CMYK-based profile, check if "Process Black" is enabled.
   • Scroll to one of your "problem" pages which does not print its gray output as you want.
   • Move the mouse over the gray area.
   • Now note how the color values in the Separation pane change when you move the mouse: Does it indicate "enough" in the Total Area Coverage value to make the printer mark the gray background on the paper? If not, click on "Ink Manager" to change settings for Type, Neutral Density and Trapping Sequence.
   • If it still does not work: enable the Object Inspector in the "Preview" pane.
   • The lower, larger preview pane may be empty at first.
   • Now click on one of your gray-background problem areas.
   • The lower pane now fills with a textual listing detailing all the color settings for that page object. Tell us what is written in there....

You could use HTML instead of word documents.

Not only is it a standard and easily viewed, but you can actually define different stylesheet for screen and printer.

Depending on your needs, you can knit the markup by hand or customize TinyMCE for your needs.
Or, as is quite common, you could use a wiki system to write your documentation, which would also give you all the features of a wiki (versioning, linking, searching, tagging etc.).