Create a Black Background with White Text
The Problem:
I need to print white text against a black background. I've changed the font color to white, but I'm just getting white text on a white backgroundin other words, sweet flatulent alpacas.
The Solution:
You need to set the background color of the paragraphs involved to black. Drag down the left margin to select the paragraphs, choose Format 
Borders and Shading, click the Shading tab, and click the black square in the Fill list. (The color name rectangle will show "Black" when you click the right square.) Choose "Solid (100%)" in the Style drop-down list, and click the OK button.
If you set the background to black, you can leave the font color set to Automatic, and Word will automatically make the font color white so that it contrasts with the background.