Is it possible to have a blank slide other than black?
How?
The “Blank Slide” is translucent and the black color is actually the background color of your document. You can change the background color in the document settings. If you need to have different colors in your show, you have to create images with this color and don’t use the blank slide but those images.
I made me a white slide in photoshop with can be colored within Fotomagico later. This way I only have one file in the FotoMagico folder which can have any color I need in the project.