Whether you should order your design in color or black & white largely depends on the surface you’ll be projecting on. If you’ll be projecting on a white surface, color designs will show up well. If you’re projecting on a non-white surface (such as a wood floor or a red wall), the design will take on some of the color and pattern of the surface, and will not be as bright as it would be on a white surface.
If your goal is for your projection to be as white as possible, you should project a black & white design. If your design must be in color, try to choose light colors, as they will project much better (ie, brighter) than darker colors.
If you choose to project a color design, we highly recommend also loading a black & white version onto your thumb drive prior to your event. This way, you’ll have a backup plan if the color design doesn’t look good where you’re projecting it.
Finally, if you’re projecting a monogram, chances are that you’re also using uplighting. Bright white designs surrounded by uplighting (such as in the photo above) look very classy! Depending on the color of uplighting you’re using, it can wash away a colored design.