Just as the modulation of your voice plays a big role in how your message comes across, the size of your exhibits can serve to emphasize, obscure or overwhelm your message. If a number is of signal importance, blowing up a document containing the number and other information may only serve to blunt its impact. Do this again during argument. The jury will immediately appreciate the importance of the figure and, more importantly, will likely remember it in deliberations.
Red means stop or hot or anger.
Green means go or envy or ecologically friendly. From childhood, we are taught that colors mean something. The judicious use of color in demonstrative evidence serves to simplify complex messages and to communicate ideas beyond the printed words. When employing color, be mindful of these extra-textual messages and exploit them where you can. If you use color to organize or communicate, be certain to use it consistently in all your demonstrative aids.