I am creating a PDF Portfolio in Adobe InDesign and I created a black background using the steps below. When I export the document into PDF form, the background turns to white.
I followed these steps to make my background black:
"Window>Color>Swatches to bring up the Swatches panel and double-click the Paper swatch. Change the Color Mode to RGB and move the Red, Green, and Blue sliders to 0 to change the swatch to Black. Click OK."
Any help with this matter would be greatly appreciated.
You misunderstand what paper is for. Paper is quite simply the absense of ink or color.
By changing it, all you've done is show what something will look like printed on black paper. If you really want a black background you'll need to draw a frame, fill it with black and place it on the master page on it's own bottom layer. Lock the layer to prevent any problems.