Turning off all colors and background images in beamer

Question

Is there a command to turn off all colors in beamer ?

I have a tex file (beamer) where I have used a lot of colors. Just in case, the colors don't show well on the projector, I wanted to turn off all colors. I am looking for a single command to do this.

Is there a similar command to turn off the background images for all the frames too ?

I am using the theme: Juan-Les-Pins.

Answer 1

For turning colors off (i.e. making them gray) add to the preambule:

\selectcolormodel{gray}

For turning off background images (assuming you are using \usebackgroundtemplate to set them) add to the preambule:

\renewcommand{\usebackgroundtemplate}[1]{}