Well yes and no actually. Projectors can't produce black (absence of colour) so they typically do so by increasing the contrast with respect to surrounding area

Well yes and no actually. Projectors can't produce black (absence of colour) so they typically do so by increasing the contrast with respect to surrounding areas (that, and you turn the lights off). So to draw black text, you need to shine white around it. But yes, in general you're right. If we draw text in blue for example, we should be able to get away with this. Again, more testing required... :-)